trough, mash and wort

How do you collect the wort when you have mashed in a trough in the ground?

The main problem, obviously, is that you can't lauter and sparge in the same way that you would if you had used a wooden tub as a mash tun with a spigot, or if you had a bespoke lautering and sparging vessel. When the trough is in the ground, it's a different story.

There are thousands of sites throughout the British Isles that archaeologists know as Burnt Mounds. All that remains is a large pile of fire cracked stones and the remains of a trough lined with either stone or wood. If you have never heard of burnt mounds before, I suggest you have a look at an earlier blog which explains what they are and some of the interpretations. Archaeologists agree that they were used to make water hot. This was achieved by heating rocks in a fire then putting them into the trough of water. What you do with that hot water is up to you. There are many possibilities. Some interpretations include bathing, others suggest cooking meat and some archaeologists think that they were used as a sauna. Another function is as a mash tun. With the discovery of chaff and grain in an oak trough excavated in Wales in 2008, a mash tun is a strong possibility.

Trough mashing at Bressay, Shetland

Replica trough at Bressay, Shetland, surrounded by fire cracked stones

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A few years ago, we mashed in a full sized replica stone trough, based on the one from the Bronze Age burnt mound site on the island of Bressay, Shetland.

The original trough and buildings were moved stone by stone, since it was in danger from coastal erosion.

A replica trough and hearth was built beside the Bressay Heritage Centre, for experimental archaeological work. It's been used to dye wool, it has been used as a bath and also as a mash tun by archaeologist Dr Lauren Doughton in her experimental work.

We were there in the summer of 2011 to mash some malt with her when she was working on her PhD about burnt mounds and troughs. 

The weather was rough, even though it was mid July. Buffeted by the wind and rain, we managed to run a mash and collect some of the wort. Our time was strictly limited because we had to catch the last ferry off the island and get back to our tent. A full set of pictures of the day's mashing, collection of wort and the final brew can be seen here on my Facebook page.

Brewers usually want to obtain as much wort as they can from the mash. There is potential for lots of waste from a trough mash unless you can find a way of maximising the wort extraction. The most obvious technique might be to let the grain settle to the bottom of the trough, then scoop the wort out using a jug or a bucket or something like that. It's tricky, as we discovered. Nevertheless, it works. Inevitably there will be bits of husk in the wort. This is not a problem. They will sink to the bottom again and it is easily possible to obtain a clear wort for fermentation from a trough mash.

Locally sourced clay was used to seal the corners of the replica trough before we began the mash.

Water was put into the trough. It became slightly murky, a grey colour from the clay luting that we had used to seal the trough. We were a bit worried, however, we did not need to be concerned because the resulting ale from this experiment was delicious, sparklingly clear and bright, perhaps the result of our accidental addition of clay to the water.

The hot rock rolling team, from the fire into the water.

The technique of rolling hot stones from the fire into the trough of water had been perfected by Lauren and her team in previous runs. Using garden forks and spades, the hot rocks were expertly rolled down the slope and into the water.

When the water reached strike temperature, 50 kilos of crushed pale malt was added to the 200 litres of water and stirred with a garden fork. You know when the water is the correct temperature for the strike, around 74 degrees Centigrade or thereabouts, because this is when you can clearly see your reflection in the water, no ripples, no steam. We double checked with a thermometer.

The strike:adding the crushed malt to hot water.

The saccharification takes about an hour and it's crucial to keep the mash temperature right for that time, adding hot rocks and stirring as necessary. We put a wooden board over the trough, to help keep the steam and the heat in. It was a good conversion of starches into sugars, a successful mash. The finished mash, when settled, was a deep dark brown and it tasted very sweet.

The finished and settled mash - the next job is to collect the wort and ferment it.

For non brewers, I should emphasise that wort is not alcoholic. Sugar ferments into alcohol, starch does not. The saccharification that happens during the mash is a crucial part of the beer brewing process. Fresh wort is very sweet and prone to all kinds of bacterial and fungal infections. On the three occasions when we have been too tired to process the mash after a demonstration, the next morning the mash was fizzy and sour. Wild yeasts and lactic bacteria infections had ruined it. It was useless. Wort must be collected as soon as it is cool enough to take the yeast. The yeast ferments sugars into alcohol. Herbs or hops preserve and flavour the ale or beer.

We were short of time and collected as much wort as was possible. The brewer used jugs, buckets and plastic containers to scoop from the trough. We had, of course, taken the stones out first, when they were cool enough to handle. The process of collecting the wort was hard work and we only managed to get about 6 gallons out of the trough before we had to pack up, load the van and catch the last ferry back to the Shetland mainland.

The brewer collects wort from the trough. The stones have been removed and are on the heap.

The wort was put into a fermentation vessel, yeast was added and the fermentation vessel was kept warm using sleeping bags as insulation. After about four or five days it had fermented into a fine, clear and strong ale. We used a handful of dried meadowsweet flowers as a preservative.

This is how we should have collected the wort
On the ferry back to mainland Shetland we realised that we had made a mistake. We should have piled the stones up in the trough to make a sort of dam, then we could have put the mash to one side and the wort would have been so much easier to collect. This is how the Moore Group archaeologists collected the wort at their trough mash demonstration at the Sixth World Archaeology Conference in Dublin, 2008.

They made a wooden trough and painted the bottom part with bitumen to ensure that it did not leak. They correctly assumed that the University authorities would not allow them to dig a big hole and set their trough in the ground.

Moore Group archaeologists filling the trough with water at WAC 6, Dublin

They heated the stones on a fire, dropped them into the water and added the crushed malt when the strike temperature was right. It was this hot rock mashing demonstration that inspired us to stop mashing in pottery vessels and start using troughs, wooden tubs and hot stones.

Here are some of my photos of the Moore Group's event:

1 heating the rocks

2 heating the water

3 saccharification: the mash

 

4 the stone dam, mash and wort separated

5 settled wort and mash

6 collecting the wort, it's cloudy because it has been stirred up.

Hot rock mashing is a spectacular process, the stones sizzle as they hit the water, the mash saccharification happens right before your eyes and the aroma from the mash smells delicious. This is a mysterious, magical transformation from grain starchiness into fermentable sweetness. Surely this would have been an event that would have amazed and impressed people in prehistory, just as much as it does in modern times.

Collecting the wort like this, by creating a dam of stones, is an extremely efficient way of doing it, perhaps even allowing for sparging. Once the first runnings have been collected from the trough, more hot water can be poured gently through the mash, thus releasing more wort for the brewer. There would be very little waste and a good quantity of wort could be collected.


Is there any archaeological evidence for the collection of wort like this?

It is rare that prehistoric troughs are excavated with the stones still within them. If you have excavated one like this, I would love to hear about it. Excavations in 2013 by Wessex Archaeology at Kingsmead Quarry, Horton, in Berkshire, England revealed the remains of four neolithic buildings. They were interpreted as having been 'houses', which is often the case with these discoveries. I do wonder how many of these neolithic 'houses' might have been used as barns or as buildings where the grain was stored and processed. But that's a story for another blog.

One of these four neolithic rectangular timber buildings at Horton caught our attention when we were looking at the pictures online. There appear to be some fire reddened rocks close by one of the buildings, in a heap. The buildings are, as always, interpreted as "houses". But were they dwellings? Or some other kind of building, like a barn or grain processing building? See Wessex Archaeology's page about them here. 


The red rocks look rather like modern bricks. There seems to be no mention or discussion of them on the web page. Maybe I missed it. However the stratigraphy indicates that they are contemporary with the building. So, are these stones an indication of hot rock water heating technology at neolithic Horton? Were they piled up in a wooden trough that has long rotted away? What were the people doing in and around this rectangular wooden building, over 5000 years ago?

I cannot answer these questions. I am nevertheless intrigued by this discovery. And so I finish this blog with a close up (thanks to Graham) of those mysterious fire reddened stones and welcome interpretations, comments and discussion.

a close up of those mysterious fire reddened stones beside the neolithic building at Horton

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If you want to know what our Bronze Age Trough Ale, with meadowsweet, tasted like, we sent some to David Connolly of BAJR (British Archaeological Jobs & Resources). Although he struggled to open the parcel, he gave his opinion on the ale's flavour and strength.

It is sometimes said that prehistoric ale was weak, cloudy and sour and that it tasted disgusting. We disagree.

Here is the link: https://www.youtube.com/watch?v=wpvPi25TTOI

Quinn, B., & Moore, D. 2009 ‘Fulacht fiadh’ and the beer experiment’ in Stanley et al (eds) Dining & Dwelling. NRA Monograph Series No. 6, 43-53, NRA, Dublin.

lauter and sparge

When the brewer has mashed in, he or she needs to separate the sweet wort from the grain husks. This is achieved by lautering and sparging.

It's a crucial part of the beer making process.

The previous blog was about the ancient magic of the mash tun, where the brewer transforms grain starch into sweetness. The saccharification, a process that is driven by the starch converting enzymes in the partially germinated grain, the malt.

At the end of the mash the contents of a mash tun are sweet, with the grain husks mixed up with the liquid. Although the brewer calls it the mash, it has not been physically mashed up, as you would mash potatoes for example. It's more like an infusion, when you put the leaf tea into the pot with hot water, then allow it to mash for several minutes.

In the brewer's mash tun you could be fooled into thinking that the grains are still whole - they look as if they are. But the starchy endosperm is gone, what looks like a whole grain is just the husk with very little left inside.

the contents of our mash tun: pale malt, roasted barley & wort

Lauter and sparge are wonderful words that mean nothing if you have never done it. They are a crucial part of the transformation of grain into ale. Many beer recipes don't use these words. You are just told to 'collect six gallons of wort'. The writer of the recipe assumes that you know how to do this.

Lautering is when you collect some of the wort and then, gently and carefully pour it, or trickle it, through the mash. Keep repeating until the wort runs clear, then collect the clear, strong first runnings. After that, you can begin to sparge. This involves running hot water through the mash to obtain several further gallons of weaker wort. How much wort you collect depends upon how much mash there is in the mash tun and what strength you want the resulting ale or beer to be.

For further details, see the brewer's post about wort which gives specific gravities and more information about wort.

There is a detailed explanation of some of the aspects of lautering and sparging by the brewer and writer John Palmer, from his excellent online book 'How to Brew'. It is,of course, the modern home brewer's perspective and one of the most comprehensive descriptions of how to lauter and sparge that I know of. His next chapter, about the importance of crushing the malt is also well worth reading.

The malt that goes into the mash tun should be lightly bruised, as they say in Orkney. Just enough to break the husk but not enough so that it has the consistency of flour. Too floury and you will have a stuck mash. This means that the hot water will not trickle through the mash and it's almost impossible to obtain the wort. No brewer wants that.

The interesting thing, for me, is how lautering and sparging was done in the past.

Today, a modern all grain home brewer can buy a mashing and sparging bag which sits neatly inside the mash tun. This is how we and many other home brewers mash, lauter and sparge.

First, the mash bag is put securely into the mash tun which has a tap near the bottom. Tie the string nice and tight. Add the required quantity of crushed malt and hot water, leave it for about an hour to mash, maintaining the temperature at around 67 degrees Centigrade. When the mash is done, all you need to do is collect some of the wort in a jug and pour it carefully through the mash. Keep doing this until the wort runs clear. This is lautering. Inside the mash tun, the bed of grain has settled and consolidated, creating a natural filter of grain husks that is held in place by the mesh at the bottom of the mashing and sparging bag.

Then you run off and collect the first runnings; this is very strong wort, very sweet. You can collect further wort by sparging. The more wort you collect the weaker it becomes. Hot water is trickled through the mash and several gallons of wort can be collected in this way. It's not absolutely essential to lauter. It's possible to go straight to sparging. The wort will be cloudy with lots of particles of grain in suspension. Leave it for a while, they will settle at the bottom of the container.

Lautering: we use a jug to collect the wort

Sparging: first runnings, the clear wort is collected

In the days before mashing and sparging bags, how did people collect the wort?

There would be a small hole in the mash tun, either at the bottom of the tub or at the side, very close to the bottom. They used a bed of straw, juniper branches or other fibrous material at the bottom of the mash tun, this would give the grain husks a place to settle and help the grain husks to form the natural filter. The fibrous material would be held down with stones, so that it does not float about in the mash. This traditional method of mashing (they call it masking) and drawing off the wort is described in the malt making and brewing chapter of Mary Scott's book (1967) Island Saga: the story of North Ronaldsay. It was written by her brother William, presumably because he was one of the island's brewers:

" The vat had been prepared beforehand by taking a good handful out from an oat sheaf and spreading it across the tap at the bottom of the vat, and then covering the straw with a stone shaped somewhat like a half moon - the straight side resting on the bottom of the vat and the rounded part fitting snugly to the round of it. The stone would be tilted to an angle of approximately 45 degrees. The stone was to keep the straw in place. 

Masking is then proceeded with using alternative pailfuls of water from the boiler and the first potful that had cooled off somewhat. If boiling water were put on the malt it was liable to stick - that is, it might all set in a gloggy mass, and no liquid could be drawn off. In the breweries I suppose they will put the water on at a certain temperature; there was no thermometer used here, just guess work."

After the mash, or masking, the wort must be drawn off. This is how it was done:

"The vat was allowed to stand for two hours. The boiler was by this time going full swing again ... when the two hours were up it was time to set about drawing off the wort. 

You put a pail under the tap, pulled out the plug, and, if everything was right, the liquid would run off in a beautiful amber stream. It was a great relief when you saw it was running off clear. The first pailful to be drawn off  might have some settlings or groot in it - that is some of the dust or fine stuff out of the malt - so you would tip that pailful back into the vat, for the groot would take a long time to seep to the bottom of the vat again."

I first came across this description of traditional mashing, lautering and sparging techniques when I was doing research in the Orkney Library over ten years ago. At the time I didn't imagine that there might be corroboration or that there are brewers still using these techniques today. Not in Orkney, but in Norway, Lithuania and Latvia. The tradition of making farmhouse ale continues in these, and other, countries and it's possible to meet the brewers and see how they make malt and ale, thanks to this blog by Lars Marius Garshol. He has been visiting them, talking to them and writing about them. It is wonderful research.

Straw, juniper branches and even raspberry canes can be used to help create the filter bed in the mash tun. In this blog, Brewing in Morgedal, Lars tells the story of how he found farmhouse brewing alive and thriving in eastern Norway. The brewers, Halvor Bjåland and Terje Haugen and their apprentice, Bjørn, make ale in the way of their ancestors. I am sure that these methods and traditions go back to medieval times, to the Viking era even. In this blog you can see photographs of the brewing process, including the stones at the bottom of the mash tun holding down the juniper branches and you can see the wort being collected by sparging.

In another of Lars' blogs he writes about farmhouse brewing in Denmark. Here the tradition has almost died out, but not quite. There are some great descriptions and images of lautering and sparging, using hot water and large wooden tubs as mash tuns. I recommend reading through his blogs. It might take you a while, there is a tremendous amount of detail. It's valuable information and an important record of local traditional malting and brewing.

Archaeologists and anthropologists, as well as maltsters and brewers, would benefit from reading, at the very least, some of these blogs. It tells a story that relates to the history and prehistory of making malt and ale in Northern Europe.

Excavations at Must Farm in the Fens of England are drawing to a close. Here, archaeologists from the Cambridge University Archaeological Unit are slowly uncovering a very well preserved Bronze Age village. It seems that there was a fire, the houses and contents burned and have been preserved in wet anaerobic conditions. Archaeologists are finding the remains of wooden buckets, pots with food contents intact and worked wood.

One of the most intriguing and exciting discoveries, for me, was the pot that contained both carbonised grain and some fibrous material. I wanted to include a link to the photograph here, however it's on their Facebook page and it does not seem possible to do that ... a few days later and now it seems to work see here

Why should a fairly large Bronze Age pot contain these two organic substances?

Could it be that the pot was being used in part of the ale making process? Not being involved in these excavations myself, all I can do is speculate. At this moment, I can't think of another reason why the pot contained fibrous material and grain, but there may well be another explanation. Please let me know what you think this might be.

That's all for now, in the next post I shall be looking at how to sparge when you are mashing in a large trough in the ground.

saccharification or what happens in the mash tun

I'm picking up the blog again, after taking quite a long time off. To my surprise, folk have been reading our past posts, so thank you very much indeed for that.

One of the reasons that I started this blog was to try and deal with some peculiar misunderstandings about how beer and ale are made. In the archaeological and anthropological literature you can read all sorts of odd things about brewing beer in prehistory and how it was invented. Malt is rarely mentioned.

I have read that "... beer was invented when some barley got wet in a bucket and then it fermented" or, and I read this very recently, that "... beer is one of the most important of human inventions, as it is likely to be one of the key reasons that farming was started, in order to grow hops for brewing ..."

You need malt, not hops, to provide the fermentable sugars to make beer and ale. This blog is about what happens to the malt in the mash tun - the transformation from grain starch into sugars.

Most people don't have the opportunity to see or to experience this magical process. We are fortunate, we have our own mash tun in the garage and we regularly make some very tasty ale and beer, using crushed malt that we buy directly from the maltster. We can go online and buy the malt. It's delivered to the door. We buy 25 kg at a time and it's always very fresh and good malt.

Our mash tun can take about sixteen or seventeen pounds of malt and we usually make about ten or eleven gallons of beer. That lasts us a while, so we don't have to make it too often.

We can choose how strong or weak we want the beer to be. We do this by deciding how much malt to use and how much water to sparge with. We can add hops or herbs, whatever we decide to do. In the past we've made some very good ancient ales in our mash tun - meadowsweet is the usual herb of choice because we live on Orkney and it grows profusely here. So we can go and pick it in July/August, dry it, store it and use it whenever we want to. We'd like to try other herbs. I'm just starting to grow a brewers herb garden, so far I have yarrow, heather, meadowsweet and angelica. Mostly we use hops.

What happens in the mash tun? Saccharification. The creation of sweetness that can be fermented. Grain starch is converted into malt sugar in the mash tun by enzymes in the malt.

Where do the enzymes come from? Basically, when any grain begins to germinate, starch converting enzymes are activated in the aleurone layer of cells, just beneath the grain husk. These enzymes convert the starch of the endosperm into sugars, the food source for the growing plant. The maltster's job is to begin germination, then stop it and dry it, very gently, at just the right moment. The craft of the maltster goes back to the dawn of grain agriculture. The first alchemy. 

Saccharification is an essential part of the brewing process. The brewer takes the lightly crushed malted grain and adds it to hot, but not boiling, water in the mash tun. Enzymes in the partially germinated grain re-activate in the mash tun and convert the grain starch into malt sugar. The process takes about an hour.

Here's our mash tun:

The strike: the moment when crushed malt is added to hot water

The aroma of a mash is distinctive - it's a strong, sweet, delicious smell. Recently we went to a meeting about recreating old beer styles at Fuller's Brewery in Chiswick, London. As we approached the brewery, even though we could not see it, we knew we were going in the right direction because we could smell the first mash of the day. Exactly the same smell that we get from our little mash tun in the garage.

The process is the same, no matter what the size or the shape of the mash tun.

A few years ago, I went to the Eindhoven Open Air Archaeology Museum and used an earthenware bowl to demonstrate the saccharification - how to gently heat crushed malt and water over the hot ashes of a fire and make sugars. In the photograph below, you can see the white crushed malt in the bowls by the hearth. For me, that's a little over crushed, but it still worked just fine for the saccharification. In little over one hour, the starchy crushed malt had become a mash of delicious malt sugars, as you can see in the large earthenware bowl in the hearth.

Saccharification in a hearth at Eindhoven Open Air Museum.
The beautiful bowl was made by Flor Buchuk Gill, she was the potter at the Open Air Museum at the time.

The equipment is very simple. The technique is not complicated. There is no need to understand the complex biochemistry that goes on in the mash tun. All you have to do is get the details right and you will get a result. Heat some crushed malt with abundant water at temperatures not exceeding 67 degrees Centigrade and the enzymes will re-activate. If the temperature is too high, then the enzymes are destroyed. 

The next stage is to separate the sweet liquid (the wort) from the mash. This is done by sparging, washing hot water through the mash and collecting the wort. I shall save that for the next blog.

Some people think that the beer brewer's mash tun is something like the wine maker's tub. They are not at all the same thing. They are completely different processes. Perhaps the word 'mash' is confusing.

Making wine, as most people know, involves treading or mashing grapes into a pulp, then syphoning off the juice and fermenting it. When making ale or beer, you have to make the sugars first, and this happens in the mash tun.

Some people make 'country wines'. Among the most popular are dandelion, parsnip, nettle and elderflower. Each wine making event involves gathering the ingredients and then buying a few kilos of sugar. Dandelion flowers, for example, are mixed with hot water and a kilo or two of sugar. Here's a typical country wine recipe. There are loads of recipes for these so called country wines. They are all pretty much the same. They all involve several bags of sugar.

As has been explained in an earlier blog, flowers, nettles or parsnips do not provide any fermentable sugars, just flavour.

I can understand why some people might be confused if they have never seen inside a mash tun or if they have not made an ale or a beer using malted grain. For most people today, seeing what happens inside a mash tun is not part of their everyday life and experience.

However, a few hundred years ago, making the malt and brewing ale and beer at home was a common activity. It happened on farms and in large households. It was a household task. In the past, when making the malt and the ale was a regular event, it would have been something that people were familiar with.

Today it seems to be a mystery to many.

What is Wort - a brewer's perspective

Hope you had a grand Yule and that you enjoyed the midwinter celebrations. We wish you all the best and A Happy New Year for 2015. There has been a bit of a lull on ancient ale blogging in the last couple of months, however we aim to correct this in the New Year and get back to writing again.

This one is about the Wort. Graham wrote it several months ago. It would make a good response to a short article "Beverage with heritage" that we read over the holidays. It was published in the Christmas and New Year Edition of New Scientist magazine, the 'one minute interview' with Patrick McGovern, director of the Biomolecular Archaeology Project for Cuisine, Fermented Beverages and Health at the University of Pennsylvania Museum. The question is asked: how does ancient booze compare with the modern stuff? The answer includes that "they wanted to be sure they had enough sugar to get the fermentation going, so they took whatever they had that contained sugar and mixed them together."
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This idea of 'mushing loads of random sweet stuff together to make alcohol in prehistory' seems to be a commonly held view amongst non brewers. Merryn wrote a blog about desperately seeking sugars a few months ago, which tried to address the issue and dispel this myth.

Here is Graham's perspective, a beer brewer's explanation of what wort is:


Wort (pronounced wirt, not wart ) is the Juice of the Barley, well not quite, but almost very nearly so. It is a thin, runny, very sweet but very sticky liquid, straw coloured through to brown. It is effectively a thin synthetic honey substitute. Ale made from wort without preservatives or flavouring actually tastes a lot like mead made from honey.

Wort is the liquid sugars extracted from malt, that is to say, partially germinated cereal grains - barley, wheat of all varieties, oats and even millet, but not rice or maize. It is the primary source of fermentable sugars in making ale or beer and always has been. It is relatively easy to make a sugar solution of at least 10% from malt, and then to wash further sugars from the grain down to a realistic level of 1-2%,  "small beer" level and, of course, anywhere in-between. This compares very favourably with other natural sources of sugar like birch sap, which is between 0.5 and 2% sugar, which would only make a small beer. So adding birch sap to a brew would only dilute it, not strengthen it as some scholars claim.

Wort is made by "hijacking" some of the natural processes of the grain's life cycle.

As part of the growing process the germinating grain must convert it's energy store, starch, into sugars so that these can then be built into cellulose, the structural skeleton of the roots and shoots. This requires the liberation of the two amylitic enzymes, alpha and beta, which are little like ptyalase, the enzyme in saliva that converts starches into sugars.

If this growing (germination) process is halted when the most enzymes are present and little of the growing structure has started, it will be good malt.

So, to make wort you lightly crush the malt and mix it with hot water at about 65 degrees Centigrade. Keep it at this temperature for anywhere between half hour to about 2 hours, depending on your style. This is called mashing. Then you drain the clear liquid sugars from this mash by lautering, which is yet another story. This gives you a strong wort. Then you can wash further sugars from this mash, sparging, to get a weaker wort.

Brewers measure the potential sugar and therefore alcohol of a wort using "specific gravity". Water is 1000. David Line in his book "The Big Book of Brewing" explains this in great detail in chapter 18.

This was my "Bible" when when I first began brewing beer 32 years ago. David Line was a pioneer in his time, explaining what the processes were, how they were done and why. He also explains different methods of mashing using simple equipment and this has been very valuable to me in re-creating the ancient and traditional crafts of brewing ale.

So to recap: wort is a golden brown, very sweet, very sticky, runny liquid that contains most of the potential sugars from the malt. It can be made to a variety of strengths e.g. Arctic Ale.

To illustrate this I will give you the results of one of my recent brews.

The recipe is loosely based on David Line's "Brewing Beers Like Those You Buy" page 88, Gales HSB. One of my favourite beers, sadly no longer made. I found his book to be an excellent collection of recipes for good Ales and Beers that could be bought in the late 1970s and 80s. Large brewery's methods have changed since then and sadly many of the modern renditions taste nothing like they used to.

15lb 8oz of crushed pale malt, Munton's Perl Blend, were mashed with 5 gallons of water, inside a grain bag, in a Peco Electrim mash-tun. The strike temperature was 70 degrees Centigrade and as the grain was added slowly, the temperature fell to about 60 degrees Centigrade, and was then raised back to 65 degrees Centigrade.

The mash tun was unplugged and covered with a sleeping bag to maintain the mash temperature. It was left like this for 2 hours.

From this I lautered 3.5 gals of wort which was nearly 1080OG.

wort: the first running

measuring the first running

This was followed by sparging. The first gallon of wort was 1062OG, the second 1048OG, and these, together with the 3.5 gallons, were boiled in an Buffalo 40 litre boiler with 1lb of dark soft brown sugar, and 4oz of molasses (these are the in the recipe and I think the molasses adds a certain something to the flavour) for one and a half hours. This produced 5 gallons of 1084OG. This was fermented in two fermenters.


A further 5 gallons of wort were sparged of 1036OG, 1020OG, 1012OG, 1006OG (this was very pale and weak) and finally 1014OG left to drain overnight. This was again boiled on the old hops, because there is an awful lot of sugars left on the hops. This gave 5 gallons of 1024OG, which was added to the two fermenters. At the end of primary fermentation this gave 10 gallons of 1008 final gravity.

The average of 1084 and 1024 gives an OG of 1054 for the 10 gallons. According to David Line's graph (on page 147 Big Book of Brewing) gives a strength of 7.5-1.1= 6.4% alcohol.

This was quite a surprise to me, for I haven't been measuring the gravities for some time, and I never expected to get this much beer from 15.5lbs of malt.

A recent comparison with a commercial beer, Scapa Special 4.6%, suggests that my beer was no stronger, so maybe there is something wrong with my figures.

But it did make me think that I may be over-sparging my wort and that this could be contributing to the haze, and tannin like bitterness. So I have increased the malt to 17lb 8oz, and now I am getting a much nicer beer.

For those of you who will never meet malt, or a mash tun there is an alternative. Go to a whole food shop and buy one of these.

As best as I can estimate, this jar contains 11 fl oz of malt extract weighing 16oz, so this makes a density, specific gravity, or OG of 1450 or so. Dilute this with 4 imperial pints of water and you will have a re-hydrated wort of about OG1054.

Wort is a brown, runny, very sweet liquid that is extremely sticky when it dries. It could be described as a kind of dilute synthetic honey, that is very ancient in origin and is possibly the first process that was ever made with cereals. It could be that cereals were first cultivated, not for their staple qualities e.g. flour, gruel or bread, but instead for their status potential, sugars.

Many of the early settlements in the Fertile Crescent had special buildings with smooth floors, made of beaten earth, clay or lime plaster which are ideal as malting floors. All that is then required are containers within which to heat the crushed malt and water (the mash) to make a sweet wort. Merryn's M. Phil, entitled Barley Malt & Ale in the Neolithic (1999), looks at this, and the archaeological evidence for it, in some detail. One particular site, Beidha, was excavated in the late 1950s by Diana Kirkbride, a member of Robert Braidwood's team. She describes a smooth plaster floor with 'thousands of grain impressions'. This is probably a malting floor. The site is dated to the 8th millennium BC.

There is a Biblical expression: "The land flowing with milk and honey". Some Biblical scholars have made tortuous explanations to explain this phrase - they write about how wild bees' nests in cracks in the rocks would ooze honey in the hot sun. More informed scholars explain that this phrase refers not to bee honey, but rather to some kind of artificial sweetness, perhaps made from figs or dates, or maybe even made from grapes.

This must be because these scholars do not recognise nor do they understand that cereals can be a source of sweetness, if processed correctly.

I think that this phrase 'land of milk and honey' refers to milk and wort. It is a metaphor, or a description of a land that is good for both cows and for growing grain.

It seems that Biblical scholars have overlooked the fact that wort (liquid sugars made from the grain) was once commonplace in Egypt and Sumeria, otherwise they would not have been able to make beer. This was probably common throughout the whole Fertile Crescent and the Biblical Israel.

With the rise of Islam in this area, alcohol has been proscribed. There is no further use for malt or wort, so the practices and knowledge of malting and mashing have died out completely there. Archaeobotanists and archaeologists who have done field work on cereals in Turkey and the Ancient Near East seem to be unaware of the malting, the mashing and the wort. It is outside their experience and so it is understandable that wort has been overlooked in archaeological interpretation.

Today Bouza is made, it can be described as a type of beer, however it is a wheat based beverage made by lactic fermention. It is no longer alcoholic.

So, why do I bother to go to all the trouble of mashing, lautering, sparging, boiling and all that washing of brewing equipment? After all, it takes a whole day, a huge amount of effort. The answer is that all of the Beer Kits that I have ever used produce a beer with a kind of metallic flavour. The Kit contains a large can of Malt Extract. No amount of boiling with extra hops, or anything else will make it taste any better.

I make my beer with the simple, basic ingredients. I use traditional techniques to make the wort because I think it makes a better tasting beer. At least, when everything goes to plan, it tastes good. Even when it's bad it is often not much worse than some of the bad commercial beer available in supermarkets.

Beer is changing, with the way it is made. Some commercial beers, in cans, bottles and on draught have this unpleasant metallic flavour. They have been made from malt extract.

I was disturbed recently by looking carefully at the contents lists of commercial beers. Some like Scapa Special say that they are made from "maris otter pale ale malt", or others "a blend of pale and roasted malts". I know these are made "from the grain" and not with malt extract.

Some lagers and stouts are labeled as containing barley, wheat and oats, with no mention at all of the malt.  I can't help but wonder if they have been made from syrups, much like the high fructose corn syrup so popular in the processed food industry. This could explain the uniform blandness of some of these cheaper beers.

The origins of the Viking bathhouse myth

We have spent some 10 years arguing that that the "first farmers", the Neolithic culture that brought cows, crops and ceramics to Britain 6000 years ago, possessed the material culture necessary for turning cereals into ale, and that there is sufficient archaeological evidence to merit investigation. Nobody in the archaeological community could be convinced. It is still considered to be a controversial theory. We have no idea why. Maybe it is a paradigm shift too far for some archaeologists to bridge, that cereals were initially cultivated for their potential sugars, a status crop, and not for their starches, a staple crop. So we considered investigating an era in which there should be no controversy.

We visited the island of Wyre in Orkney, and inspected "Cubbie Roo's" castle. This was built by Kolbein Hrugr, hrugr means "heap", he was a big man. It is mid 13th Century and one of the older mortar and stone built castles extant in Scotland. It is a fascinating site on one of the now remoter islands of Orkney. We were surprised, amazed and overwhelmed to find a stone built "mash oven" in an outbuilding round the back. Our excitement was because this could be the oldest mash oven in Europe. This building has a stone bench, perfect as an ale store, and drains. It would be very suitable for making ale, but so far archaeologists have interpreted this as just an ordinary oven.

Cubbie Roo's mash oven, Wyre, Orkney.

the medieval brewer, stirring the mash

We are lucky on Orkney to have well preserved Viking sites. A friend and neighbour suggested that we might like to look at the drains at the site on the Brough of Birsay.

Birsay is the late 10th Century base of Sigurd the Stout and his son Thorfinn.  In the Orkneyinga Saga they are renowned for their hospitality. We can imagine the great feasts they had there. This might even be the site of Sigurd's Yule Feast, where Kari slew Gunnar Lambi's son in front of King Sigtrygg of Dublin ( pp xxvii-xxviii, Orkneyinga Saga, edited by Joseph Anderson.)

Drains are significant for brewing installations. The mashing process makes sugars from the malt and these are very sticky and messy. Any spillage or accidents have to be washed away, and the brewing equipment has to be kept clean. A brewery cannot function without effective drains.

one of the massive stone lined drains at Birsay

There is a massive drain running down the middle of what I think is the head of the Viking causeway, most of which has been eroded by the sea. To the right of this causeway, looking back to the mainland, is the so called "Viking Sauna" (see photo below) with stone slabs on edge, supposedly to support wooden benching. I heard an expert on TV saying that "they poured hot water down the drain under these benches, to keep their bums warm". I think it's far more likely to be the brew house and ale store.

not the sauna - this is the brew house and ale store

On the left of the causeway, looking towards the mainland, is a building interpreted as a "Bathhouse or Sauna", in the photo below. It looks more to me like a mash house. It has a bench and a large hearth and drains along the wall. One end has been lost to the sea, and it is thought that there was a large hall or langskaill further out to sea.

the mash house, with large stone shelf & several drains

I was puzzled. These installations are little different to the Orkney Brewery, which is just down the road at Quoyloo. Rob Hill's Swannay Brewery, also on Orkney, uses the same installations - a mash tun and fermenting vessels. How on earth could anyone think that these buildings were a Bathhouse and a Sauna? Maybe they knew absolutely nothing about how beer is made.

When I get puzzled by archaeology, I like to read the original excavation reports. This tells me what came out of the ground and there are usually nuggets of really useful information that are lost or not mentioned in summaries.

The earliest reference to 'Viking Bathhouses or Saunas' that I could find came from Dr Alexander Curle's excavations at Jarlshoff, Shetland, published in 1935, in the Proceedings of the Society of Antiquaries of Scotland (PSAS 69). He wrote that "...the presence of such a drain, and the condition of the ash deposited within it, suggest the possibility of the remains of a bath-house existing nearby." (page 284).

Curle explains that this is the first Viking settlement excavation in Britain, and that his interpretations are based upon the work of Thorsteinn Erlingsson, who wrote about Icelandic settlements. In his book  Ruins of the Saga Time, published in 1895. Erlingsson describes the components of the traditional farmstead house, including the bath-stofa or bathroom. He describes it as being part of the main structure and it is not a separate building.

Jarlshof, Shetland - is this the bath house, hof, a religious building or a brewhouse?

The structure in question at Jarlshof (see photo above) was beneath a mausoleum and it was not excavated until the 1950s by JRC Hamilton. Alexander Curle did not actually excavate it. In the foreground is a large longhearth and a substantial drain. To the rear of the building there is what looks to me like the bowl or footings of a grain drier.

So how on earth could Dr. Curle know that it was a bath-house, other than making the assumption that it was, because of the drains and and a means of heating water?

This remained a mystery to me until I stumbled across Dr. Alexander Curle's excavation report for another Viking age site, at Freswick, Caithness, Scotland, published in the Proceedings of the Society of Antiquaries in 1939, see PSAS 73 . In this, he describes a feature that, at first sight looks very much like a small Roman style bath-tub, with a large hearth and drains.

I was devastated, despite the complete absence of any mention of bath-houses in the Sagas, here was an archetypal bath-house. The Sagas describe the practice of bathing in streams, lakes and rivers. There were even open-air hot baths in Iceland, thanks to the natural hot springs there. Otherwise the Vikings habitually bathed in tubs of hot water in the andyri or porch. Even the King of Norway took his bath in a tub. 

reconstruction of Snorri Sturlussun's 'bath house' makes use of a hot spring, 
it is in the open air and is nothing like the buildings at the Brough of
Birsay & Jarlshof.

Then one day I re-read "The Vikings in Scotland" by James Graham-Campbell and Colleen E Batey. On page 198, the Viking settlement at Freswick is discussed:

"... as part of the re-examination of this building through  the surviving records, several problems became clear, the most significant being the complete stratigraphical separation between the secondary structure and the underlying drain. These could never have been associated and thus the secondary building is unlikely to have been a bath-house."

It was now obvious to me. Dr Alexander Curle was already aware of Freswick when he excavated Jarlshof, and this had influenced his interpretation. It has also influenced the interpretations of Viking sites for many other excavators and archaeologists since then. Whenever they find drains and a means of heating water, they interpret it as a "bath-house", even though the original archetype has been found to be wrong.

Interestingly the Brough of Birsay was excavated under the direction of Dr Curle's daughter-in-law, Cecil Curle, so she would have followed the family tradition and their interpretations. 

In short, most archaeologists do not know how to make beer from the grain. They certainly drink it, and they may even have made beer from kits, but they do not understand the processes, and so they do not recognise the installations in any era up until the late Mediaeval when monasteries brewed.

What a sad loss.

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further reading
We presented a poster at the 7th Experimental Archaeology Conference, Cardiff University. It can be downloaded here:

Where were the Viking Brew Houses? 


more reading (added June 25th 2014) 
We wrote a paper for the EXARC Journal, it has been peer reviewed and it is currently on the member's only section of the Journal. It will be released for everyone to access, download and read in the near future, probably later this year.

In the meantime, here is a shorter version of that paper, published in the Orkney Archaeological Society Newsletter. We called it 'Where did the Vikings make their ale?'.

Update

Lars Marius Garshol has been studying Norwegian Farmhouse brewing for a long time and is an expert in this field. The methods and equipment that he describes seem to us to have changed very little, if at all, from those of the 10C.
For anyone who wishes to understand or recreate Viking style brewing his work is an invaluable resource. Here is his Blog.

Lars' Blog


 

trough mashing, tridents, fire cracked stones and ale

introduction and update
This blog discusses some of the practical and technical details of mashing in, Neolithic and Bronze Age style. It's about troughs and tridents, hot rocks and prehistoric burnt mounds. It was first published in the summer of 2014. I've edited it, added a few more details and brought it a bit more up to date. Why did I do this? Because it's now 17th February 2022 and the World of Stonehenge Exhibition has just opened at the British Museum in London. Among the 400 wonderful exhibits are two large wooden tridents, carved from solid oak and each measuring over two metres long. They were discovered near Stainton, Carslisle, in 2013. What were these mysterious objects used for? Archaeologists were puzzled. Suggestions at the time included eel spears or hay forks, neither being particularly convincing.

There was quite a lot of discussion on social media about the various possible and probable uses for these enigmatic objects made from solid oak. I'll try and find a link to it. It was a lively and, at times, argumentative discussion.

One suggestion that Graham and I made at the time was that these wooden tridents were ideal as mash forks, a traditional tool used for stirring the crushed malt into hot water in the 'mashing in' part of the ale and beer brewing process. Initially the idea was met with some negativity and suspicion. However, it now seems to be one of the accepted interpretations and, I am pleased to report, is included in the newly published book of the 'The World of Stonehenge' Exhibition:

"The tridents may have been used for fishing or eel trapping, or in agricultural activities as hay forks, and even as mashing forks in the process of beer brewing. It is likely that farmers were using some of their cereal harvests to make alcohol for social and religious gatherings rather than consuming only sober porridge and savoury foods." 

(Garrow, D. & Wilkin, N. The World of Stonehenge, published by The British Museum, 2022 page 50)

(© Tullie House Museum and Art Gallery Trust)
This image is from a news item in Archaeology, Friday December 6th 2013. see:https://www.archaeology.org/news/1610-england-neolithic-wooden-tridents

At the World Archaeology Conference (WAC 6) in Dublin, 2008, archaeologists from the Moore Group demonstrated how to mash in a wooden trough using fire heated stones. They used a garden fork to transfer the stones into the trough.  Inspired by their brewing experiments Graham and I mashed in a replica stone trough at Bressay, Shetland, the site of a Bronze Age burnt mound, in the summer of 2011. We used a garden fork to stir the mash and, at the time, we wished that the handle of the fork could have been longer. Something like these tridents would have been perfect for the job. See our blog trough, mash and wort for more details of these experiments and demonstrations.

These two wooden tridents were carved from single pieces of oak and would certainly have been sturdy enough for the task of stirring the mash in a trough in the ground. They would also have been suitable to remove hot stones from a fire, transferring them into the trough of water in order to heat it and maintain a good mash temperature. The tridents have been dated to c3650 BC and were found in a palaeochannel at Stainton, a site associated with burnt mounds and much more. See here for more details of the excavations. 

And now, after this updated introduction, let's go back to the blog that we wrote in the summer of 2014:

what is a burnt mound?  

In Ireland, over 5000 burnt mound sites are known. In Scotland, about 1900 have been excavated so far. They also found in England and Wales. The burnt mound itself is a pile of fire reddened and cracked stones, often in a semi-circular shape as they have been thrown onto the heap. The stones were put into a fire to be heated up, then dropped into a trough of water in order to heat it. There are many things that hot water can be used for.

Archaeologists agree that burnt mound sites are something to do with hot rock technology - using hot stones to heat lots of water - but to what purpose? That's what archaeologists can't agree on. There have been several suggestions:

- they were used to cook meat. The idea is that you wrap a big piece of meat in straw and leave it in the heated water trough for several hours. You probably have to keep putting more hot stones in, as the water cools. There are easier and more efficient ways of cooking meat.

- they were a sauna or sweat lodge. I don't understand this. In my experience, a sauna has a few hot stones upon which water is splashed to make steam. You don't need a large trough of water and lots of hot stones.

- you can wash sheep fleece or wool in them. This seems to be a practical idea. Fleece must be washed before it is spun into wool for clothing.

None of these suggestions are controversial. Most people reckon that the troughs would have been multi functional - a bit like the kitchen sink only much bigger. When it was suggested that these sites could have been used for making beer, some archaeologists became ever so slightly annoyed. Although the idea was first put forward in 2007, backed by successful experimental work and sound brewing theory, it is still considered by some to be controversial. I don't know why. 

Hot rocks are ideal for heating large amounts of water to the perfect temperature for mashing, which is between 65 and 67 degrees Centigrade. Getting the water much hotter than this is very difficult. We found it impossible to get the water to boil. 

troughs as mash tuns
The possibility that they were used in the making of ale or beer was first suggested by Declan Moore and Billy Quinn of Moore Archaeological and Environmental Services Ltd. I first met them at a Conference about beer and brewing in prehistory and antiquity, held in Barcelona, October 2004. I gave a paper about the importance of malt in the brewing process. Billy and Declan asked me whether it was possible to make beer in a hole in the ground. We agreed they should have a go.

The following year, they came to Orkney to meet Graham and to learn a bit more about how to make ale and beer from the grain. They tasted the wort and were surprised how sweet it is. They tried Graham's beer and liked it. Then they went back to Ireland to do their own research into hot rock mashing in a trough. It went extremely well, and led to their now famous video on You Tube. They wrote an article for Archaeology Ireland and there have been several more articles online since then. The details of their subsequent work are on their web page.

They gave a demonstration of the technique at the Sixth World Archaeology Conference in Dublin, 2008. I was lucky enough to be there and it was spectacular. The smoke, the steam, the hot stones and the aroma of the mash! All of these things added to the magic and drama of the demonstration. If an archaeologist is looking for an impressive show of ritual, power and transformation in prehistory, then a hot rock mash ticks all the boxes. 

One day in the summer of 2009, I got a phone call from Billy. He told me that a trough with grain in it had just been found in Wales. The well preserved trough, with wood lined water channels, was excavated by Dave Chapman of Ancient Arts who went on to do some mashing and brewing experiments of his own. He was successful, as reported in British Archaeology news.

We had to try this for ourselves. So far, we had been mashing small amounts of crushed malt in earthenware bowls. It was clear that the 'hot rocks in a trough' technique worked much better. Graham made a small wooden trough, about one third the size of the real ones, and we had some fun mashing with hot stones. It is best to use stones from the land. Rocks collected from the beach explode when being heated in the fire. This is very dangerous.

We had an opportunity to mash in the replica trough at Bressay, Shetland in the summer of 2011. The same trough that was used to experimentally wash fleeces. We cleaned it well and luted the corners with local clay, to prevent water leakage. This explains the grey colour of the water in the photo below. There was initially some concern that there might be a problem. It turned out to be the clearest, sparkliest ale we have ever made. Bentonite powder, a derivative of clay, is used today to clear wine and beer.

the strike: 50 kg of crushed malt is added to about 250 litres of hot water in the replica Cruester trough, Bressay, Shetland.
We used a garden fork to stir it about.

 

A successful mash. Adding a few hot stones kept the mash at an ideal temperature for the conversion of starch into sugar, which took about an hour. We put a piece of wood over the trough for heat retention. 

crushed malt & water transformed into 250 litres of wort in the trough, enough to make plenty of ale for a feast.

cheers! our clear and bright Bressay Ale.

After taking some of the wort from the trough using jugs, we added brewer's yeast and fermented it for several days. We only had one fermentation vessel, so we could not make use of more than 6 gallons of wort.

Next morning, when we went to empty and clean the trough, all the wort had drained away. Only the spent grain was left. Although we had clay luted it, the reconstructed trough is above the local water table. Meadowsweet flowers, about an ounce and a half, were added to the 6 gallons of wort when it had finished fermenting. Also, we had a ferry to catch and so our time was limited.

The result was a strong, clear ale. You can see all the pictures of our Bressay mashing and brewing adventure on my Facebook page. The ale kept really well.

We bottled it and sent some to the Past Horizons people to taste. It did take a while to open the parcel, but I think it was probably worth it.


neolithic burnt mounds, wooden tridents and fire cracked stones
There are excavations taking place in Northumberland, not far from Bamburgh Castle, organised by the Bamburgh Research Project. Several burnt mounds have been excavated and archaeomagnetromic dates that have so far been obtained indicate that these burnt mounds were in use during the Neolithic. Pottery finds support this interpretation. The dates obtained so far are 6,230 +/- 50 years BP at 95% confidence. There is a good summary of the excavations here.

Bishop Arnold of Soissons

In December last year, there was much discussion and argument on social media about some neolithic wooden tridents that had been found at a multi period site in Cumbria, which included several burnt mounds. What were these long handled wooden 'forks' used for? Fish prongs? Or maybe they were used for catching eels? Interpretations varied amongst archaeologists.

We think they would be a useful implement for stirring the crushed malt into the hot water - the strike. The crushed malt, also known as grist, clumps together when it is being added to the hot water. It is important to stir it about. It is also necessary to stir the mash when you add more heated stones. You don't want to have hot spots, you want to maintain an even temperature throughout the mash. The fork can also be used to move the hot stones about in the trough, if necessary.

In the Bressay trough, we used a garden fork. The handle was far too short and a long handled wooden trident would have been ideal.

Bishop Arnold of Soissons (who lived from 1040 to 1087) was the patron saint of brewers in Belgium. He is depicted with Bishop's mitre and a mash rake, which looks very much like those neolithic wooden rakes excavated in Cumbria.

Several neolithic buildings have been excavated at Kingsmead Quarry, Berkshire, England, by Wessex Archaeology. They have been interpreted as houses. This site is another very complex, multi period discovery, with finds ranging from the mesolithic, neolithic and Bronze Age through to post medieval structures.

One of the four neolithic rectangular timber buildings, or 'houses' at Horton caught our attention when we were looking at the images online. There seem to be some fire reddened rocks close by the trenches that reveal the outline of the building in the photo below. What are they? They look rather like modern bricks, but the stratigraphy indicates that they are contemporary with the building. Are these stones an indication of hot rock technology at neolithic Horton? If so, exactly what were they doing in and around this wooden building, over 5000 years ago?

the footprint of a neolithic rectangular timber building at Horton, Kingsmead Quarry, with a big pile of fire cracked stones.
Details of the excavation here.

 

We looked through the reports online but could not find a reference to them. Quite a mystery! Graham managed to enlarge the section of the image with the rocks in and here it is. In close up they look even more mysterious. We look forward to reading the full excavation report to see what the interpretation of these rocks might be.

a close up of those mysterious fire reddened stones.

We would love to hear your ideas about burnt mounds, troughs, mash tuns and the possibilities of hot stone technology. This technique, of heating water and the mash with hot stones, is so successful that it has been done from the Neolithic to Viking times. Some burnt mounds provide dates that indicate this.