Sunday, 17 February 2019

Hearth mashing

In the summer of 1997, before Graham did his oven mashing work in the autumn, I'd been doing some hearth mashing experiments in the back garden. I wanted to see whether I could make malt sugars using basic equipment and facilities, something similar to that used by people in the neolithic era: an open fire and pots. I did some baking on a stone beside the fire as well. I used pale crushed malt from Fawcett's. It was simple, straightforward stuff.

Graham was dubious that it would work. He reckoned it might not be easy to meet the narrow specific temperature band, between 62 and 70 degrees Centigrade for the successful enzymatic reduction for the saccharification. But I thought I'd have a go anyway.

Replica neolithic pots were not easily available then. However the local garden centre had some suitable unglazed earthenware pots, so we bought and used them. The bowls were porous and, given they were to be used for liquids, they had to be sealed. We sealed some with beeswax, others with lard or butter. But this is another story - fats in prehistoric pots and what they might or might not represent. It's complicated.

The first hearth
Using stones from the garden, I made a small hearth and lit a fire. I went for the classic camp fire style, a round hearth. In one of the bowls I mixed some crushed malt with cold water, as below, and started to heat it in the hot embers. I had some cold water ready to cool it down, should it become too hot.

the first hearth and the start of the mash

After about half an hour, the mixture was beginning to smell like one of Graham's mashes. There was that familiar sweet, delicious, malty aroma. The mash slowly began to change colour, becoming darker brown. It tasted sweet.

Although the conversion from starch into sugars was working, albeit slowly and not very efficiently, I found it difficult to control the temperature in such a small hearth. The embers were cooling too quickly. The mash was getting cold. The hearth was far too small to be a working hearth. I never needed to use that cold water.

saccharification begins

I tried adding wood to the fire. This didn't work. The wood produced flames but not sufficient radiant heat. I moved a hot stone next to the pot, that didn't work either. Quite clearly, a lot more practice using an open fire was required.

I needed a bigger hearth. More of that later.

Making sweet barley cakes, malty biscuits: bappir
By now the large flat stone was hot to the touch. So I decided to use it for a kind of baking or mashing experiment. I had no idea what would happen. I'd never done anything like this before.

making malt flat breads or sweet bappir - what should we call them?

Crushed malt was mixed with cold water to make a thicker mixture than I had made for the bowl mash. A few little 'cakes' or 'biscuits' were gently warmed up on the hot flat stone. It was not a fierce heat. Provided that we kept splashing them with water, they too began to turn a nice golden brown colour. Water is necessary for the enzymatic reduction, both as a physical transport and as a chemical component in the hydrolysis.

After about half an hour, the malted barley biscuits began to taste sweet. This is a simple demonstration that sugars can be made from malted grain with no need for a container. I'm not sure what to call them; they are not like modern cakes or biscuits. Perhaps the best description is the Sumerian word bappir, which seems to have been a kind of beer bread.

There was no honey, dates or yeast in my bappir. The only ingredients were crushed malt and water. All of the malty sweetness came from the malted barley, by the process of the enzymatic reduction of starch into malt sugars.

The second hearth
I mentioned earlier that I needed a bigger hearth. So I built one, based upon the large rectangular hearths that we had seen at the neolithic village of Skara Brae, Orkney. It was so much easier to use than the small round hearth. I could have a fire running at one end, then rake the hot embers to surround the bowl that I was mashing in. The temperature of the mash was a lot easier to sustain for the necessary hour or so for the conversion from starch to malt sugars.

the second hearth

I could see, smell and taste the saccharification in my mini mash tun. Today experimental archaeologists talk about the experiential and the experimental aspects of what they do and what they try to re-create. In this simple hearth mashing experiment I was experiencing the aromas, the taste and the effectiveness of this simple technique.

I successfully made malt sugars from malted grain and hope that there is enough information for this fundamental experiment to be repeated by others. If not, then please get in touch and ask me about it.  

Doing a demonstration, no longer an experiment
These simple hearth mashes and making sweet bappir from crushed malted barley and water formed a part of my M.Phil thesis 'Barley Malt and Ale in the Neolithic' which was completed in 1999 and published (by invitation) as a BAR in 2004. The experiments were repeated several times. Every time the crushed malt and water became sweet and the saccharification worked. Eventually, what had started as an experiment in my back garden became a demonstration.

In the spring of 2009 I was invited by EXARC to the Eindhoven Open Air Museum to take part in a beer brewing workshop. I arrived with nothing. I had no malt and no pots. I wasn't sure what I was going to do.

Thankfully, the medieval brewers had plenty of crushed malted barley for their demonstration and they were happy to give me some. The museum potter, Flor Buchuk Gil, had some fine pots and she was happy for me to choose and use one of hers. For the mashing in demonstration I selected a beautifully made wide earthenware bowl that had been burnished to make it watertight.

mashing in a bowl and sweet bappir or malt flat breads at Eindhoven Museum

The hearth was large and round, so there was plenty of space to burn wood and use the hot embers from that to heat the bowl mash. The conversion was excellent. The initial saccharification occurred within the first hour of mashing. I was busy talking to visitors, explaining the process and what was happening. In that time I neglected to stir the mash. It became caramelised and ended up being incredibly tasty and sweet.

Some small flat stones were found. They were used to make some sweet bappir, as I had done in the back garden. Once again, the saccharification worked very well indeed. Visitors tasted the mash from the bowl and declared it to be delicious. I noticed that, at the end of the day, most of the sweet bappir or malt flatbreads had been eaten.

Pale crushed malt, a bowl mash and most of the sweet bappir have been eaten.


Making malt sugars from crushed malt requires water, but it does not require a container for that water. Malt flat-breads (aka sweet bappir) can be made on a hot stone beside a fire with nothing other than malt, stone, water and fire. This technology, or alchemy, was available to the first seed gatherers of the ancient Near East. All they needed was the knowledge and experience of malting the gathered cereal grains.

Professor Li Liu and her team at Stanford University have recently identified morphological changes in starch granules that are consistent with malting. These date from 13,000 years ago. See here for more details.

This technology could be many tens of thousands of years old, beginning with the first seed gatherers. These malt flat-breads are so attractive and tasty that people eat them. They would have been more attractive than un-malted flat-breads. Once this trick with cereal grains was discovered it would not be lost. Today we probably eat some malt every day. It's added to breakfast cereals and confectionery to make them more attractive.

Monday, 11 February 2019

brewing vintage and antique beers

 Beers from a bygone era

When I stumbled across Boak and Bailey's blog about Pollards : Only a northern brewer it took me down memory lane to when I first started brewing with all grain. It was Autumn 1982. I had just bought a house in Withington, South  Manchester. I could do what I liked, without disturbing or disturbance from shared accommodation house-mates. I had got a second hand Baby Burco boiler, formerly used for nappies, and plastic buckets and 20 litre snap lid containers.

My brewery in the garage

My first Baby Burco on the left, on it's third element, is now relegated to heating sparge water. In the middle is my last remaining beer sphere, Peco mash tun and demi-johns. Inside the blue sleeping bags there is 10 gallons of beer in the final stages of primary fermentation.

I bought my ingredients from Hillgate Brewing Supplies in Stockport, the shop mentioned by Boak and Bailey. It must have been just after the shop had changed hands from Pollard. The man running it was John Hoskins, if my memory serves me right. I would phone in an order: "Two of page 88 please" and pick it up the next day. He would make up recipes from David Line's "Brewing Beers Like Those You Buy", which was a boon for a novice brewer without any scales.

That book and it's brother "The Big Book of Brewing" were my guides throughout my initial brewing experiences. I had developed a taste for traditional cask conditioned ales as championed by CAMRA, and was determined to make my own beers like that.

The books

With the repeal of the brewing license laws in 1963 by Reginald Maudling home brewing beer became popular. David Line was a pioneer in small scale domestic, kitchen, beer brewing. He developed a lot of techniques and went on to try and recreate recipes like the commercial beers.

When we first moved up to Orkney I thought that I should get new copies of these books, as the old ones were getting a bit battered. I bought them on-line which gave me the opportunity to review them, which I did with glowing praise. A few months later I checked the reviews again to see what others had said. There was a comment for TBBoB: "This guy recommends fermenting in a trash can! Eugh, I don't think I'll bother with it!" or words to that effect.

A review for BBLTYB said "I've tried brewing three of these beers, and not one of them tastes anything like those you buy." Actually they were quite right. But they had completely missed the point that it was the beers that they bought that had changed over those 22 years and not the recipes.

So if any of you readers want to try making beers and ales like they used to taste in the 1970s and 1980s I recommend BBLTYB. I lent it to a friend who was also starting up brewing at that time. He recommended:
86  Eldridge Pope      : "Royal Oak"
87  Fullers                  : "London Pride"
91  Greene King         : "Abbott Ale"

I tried the following beers with success:
88  Gales                    : "HSB" still my favourite. Now I add 1/2lb of flaked oats for the mouth feel. I never did add the saccharine.
94  Hook Norton         : "Old Bill"
109 Shepherd Neame : "Best Bitter"
142 Stella Artois
148 Grolsch

I can still remember Stella Artois changing in the late 1980s, so that I would only buy imported Stella. That made in the UK was just not the same. Come to that when I bought some cans of Guinness five years ago, it was just not right either. To me it is so sad that these traditional beers, lagers and ales have changed their manufacturing methods and now taste nothing like their original forefathers. 

Fashions change. American citrus hops have become popular, Mango IPA and other exotic recipes, all these leave me cold. I prefer the old traditional British cask conditioned ales, and so I will continue to brew my own.

On a completely different tack, I have been wondering why it is that Merryn and I have so much difficulty in explaining the science and biochemistry of malting, mashing and fermentation to archaeologists.

David Line was an Electrical Engineer, as was my father. He was one of the engineers involved in building the National Grid after the 2nd world war, and he used to make hedgerow wines at home. I used to be a Computer Systems Engineer and I am from a scientific/engineering background. I wonder how many other brewers have a science background and if there are any with a humanities background.

I wonder if C.P. Snow's concept of two divided cultures (Two Cultures) has something to do with this communication gap. Archaeologists, anthropologists and sociologists are all usually from a humanities background. Maybe they see things completely differently from myself and other engineers. When I try to explain a scientific fact to an "ologist" they often tell me it is just an opinion. In the absence of corroborative evidence from their own literature it cannot be considered significant. Whereas to me it is a truth, like gravity and other phenomena.

Graham Dineley

Tuesday, 5 February 2019

Oven mashing

This blog is written by Graham Dineley, the brewer. The opinions are all his own.

When we first started investigating the origins of beer brewing, I was fortunate enough to have been making beer from the grain in the traditional* way for some 15 years. Brewing on a small scale of 5 to 10 gallons at a time, which would be about the volumes of some of the large Neolithic Grooved Ware buckets that Merryn had found in her research into the literature. So I thought this was quite a relevant experience. The processes for making beer can vary according to climate and equipment, but the fundamental biochemistries are invariant.

*) By traditional here I mean the European tradition, as from around the 18th Century, when brewing first became industrialised. The American tradition was interrupted by Prohibition, when malting and mashing was turned into making malt extract for the food industry. Malt extract is a late 19thC invention. It was marketed as a health supplement. When Prohibition was repealed American brewers mostly used extract, because it is a lot easier to make and to control extract brewing; their mashing arts were largely lost. Many American home brewers use extract or "brew in a bag" or a mixture. Americans would call what we do "conventional all grain brewing" see "brew in a bag" explained.

I had made enough beer and enough mistakes to have a good idea of what works, and what doesn't. So when I read the Archaeological/Anthropological literature on beer brewing that Merryn had gathered I realised that it was useless. It was largely anecdotal, confused and confusing, for it was written by academics who had never made a beer, and their source material was also from academics who had not made beer, they kept repeating the same old myths. They are considered to be experts in this field, but none of them had ever made a beer. How can one be an expert when one has no experience?

A lot of the archaeological literature on beer brewing is completely wrong. There seems to be an unshakeable idea that somehow there was some sort of primitive or primordial beer that had been discovered when a loaf of bread fell into a bucket of water, or grain in a pot was rained upon, and they then spontaneously turned into some sort of beer. It was a primitive beer, but it was steadily refined into the modern product.

I knew that this was utter nonsense for making beer requires a three stage process:

1) preparing the grains for converting into sugars : malting
2) converting the malt into liquid sugars                : mashing or saccharification
3) turning the liquid sugars into alcohol                 : fermentation

All three stages require completely different conditions, so there is no way that any two or even all three could be conflated, they have to be separate.

So I set out to see if I could make this beer-bread or Bappir that both the Egyptians and the Sumerians had used.

I could see that there was no point in baking a yeasted loaf of dough or even malt in a conventional oven, and then expect to make sugars from it. The heat would kill the yeast and any enzymes long before the bread had conventionally baked. Bappir could not be anything like bread as we know it. The naive academic assumption is that anything baked in an oven must be bread, just as there is an assumption that all querns were for grinding grain into flour to make bread.

However, I thought that if crushed malt was mixed with water into a very thick mash, and if this was placed in a very low oven, there was a chance that the mash would pass through the band of temperatures necessary for conversion and hopefully stay within that band for long enough to effect a conversion.

We had an old 1960s very heavy gas cooker that had been converted from town gas (pyrolised coal) to natural gas (methane). It had an oven with the lowest setting , gas mark 1/4. It was very much like this illustration below.

Two metal cup-cake trays were filled with a stiff mash of crushed pale malt and cold water and were put on the bottom of the oven late one evening and left overnight.

As we went to bed we were encouraged by the aroma of a mash that was just beginning. In the morning the kitchen was filled with a rich beautiful aroma and the contents of the trays was a deep brown, crispy, crusted and almost dry. I now know that what had happened was that the mashing had at least partially succeeded, and then as the temperature had increased, the Maillard reaction had created the delicious aroma and flavours. The product was baked so hard onto the trays that the only way to remove it was to add hot water. Beer sugars are incredibly sticky and make a powerful glue.

Unfortunately there was not enough to make a beer with, but it demonstrated a proof of concept. This was in 1997 and the only digital camera I could borrow was of very low resolution. I didn't take any pictures.

Those people who were prepared to taste it thought it was delicious, a bit like granola.

This is why there is no substitute for actually doing these things, to get an understanding of what is actually happening. There is so much about the brewing processes that is experiential, the smell, the colour and so many little indicators to give an experienced person feedback as to what is happening and how to regulate it. One really has to do it, to get one's hands sticky, to really appreciate the saccharification. It is one of those clubs that one can only join by doing it.

This blog is about trying to recreate this experiment, only this time I would measure, record and take pictures. I have the benefit of much more experience, knowledge and understanding. Enough for me to realise how little I really know, and how much more there is to know.

I also have the benefit of Lars Garshol's research into traditional Farmhouse brewing. It is an excellent ethnographic study of North European traditional brewing, often using equipment and techniques dating back to at least the Iron Age, e.g. wooden barrels, buckets and other wooden vessels. One needs iron tools to make staves easily.

Here is his blog on Keptinis :  Traditional oven mashing.
And here is a youtube          :  Keptinis Alus

The experiment.
Our new cooker is also gas (bottled propane), but smaller and of a much lighter construction. It would not take two cup-cake trays on one level. It also has a different control for the oven, no 1/4 only a very low S, which I take to mean Standby or pilot. As I wanted to try making a beer with this batch I decided to use one cup-cake tray and two aluminium food trays. I chose a silicone tray in the hope that if the cakes set solid, they would be easier to remove. However as I discovered the sugars will stubbornly stick to anything!

I made a stiff mix of water and crushed pale malt at 60C. This was probably a mistake, it should have been 20C. Then I found a shelf that gave a steady 70C, about half-way up the oven for the cup-cake, and put the two deeper trays on next shelf up and left it for two hours. After that I moved them to the top of the oven and turned the heat up slightly and left it for a further two hours. I wasn't prepared to leave it on overnight, because I didn't know how much gas was left in the bottle.

There was not much darkening, so it had obviously not got hot enough to cause much of a Maillard reaction. Again a mistake it should have been much hotter.

This was transferred to a mash bag, and hot water added to just cover the grains. The mash bag was drained, and hot water again added to cover the grains. A second covering produced a liquor with very little sweetness  and was discarded.

About six pints were recovered, enough for fermentation. An iodine starch test showed that it was not a complete conversion, but there was enough sugars for a 4 day ferment. Then I added dried meadowsweet flowers as a preservative, too many I think.

The finished product, quite light, maybe 3% and far too much meadowsweet, so much so that is no discernable malt flavour, but it is still drinkable and alcoholic.


I need to do an awful lot more work on this until I can reliably repeat oven mashing.

Yes it is possible to successfully mash in an oven, but it requires a very low temperature, much lower than needed for a Maillard conditioning, which again needs a very much higher temperature. The two are exclusive.

So were the Egyptians mashing with their beer bread, or were they conditioning an already converted mash? We may never know, but certainly Heirakonpolis has six large and very fine mash tuns, and also the Egyptian texts describe many different beers, of a variety of colours and darknesses.

So on balance I think that beer bread was just a way of conditioning an already converted mash, to give it colour and flavour.

We were just very lucky that our old cooker in Manchester had such a thermal inertia that it could spontaneously both mash and condition.

Saturday, 10 March 2018

mashing (and a bit on fermentation)

The beer recipes that the brewer of the house follows are inspired by Dave Line's home brewing book, Brewing Beers Like Those You Buy. This is the same guy who wrote The Big Book of Brewing, which explains the biochemistry of mashing and fermenting so well. Dave Line was an electrical engineer. He was also a pioneer of home mashing and beer brewing, enabling people to make good quality beers from the grain at home using simple equipment, authentic ingredients and traditional techniques. Published in the 1970s, these could be called heritage recipes. In the book, Line explains what mashing is, what happens in the mash tun and how to 'mash in' successfully. There are plenty of ale and beer recipes to follow, from pale ales to imperial stouts. 

The brewer bought these books in 1982 when he got his own house. Before that, he'd only used beer kits which are basically just a large tin of malt extract. That's all you can do in a shared house with a communal kitchen. Extract brewing. Since 1982 he has brewed nothing but all-grain beers, starting off  by following Line's recipes in detail, making mistakes along the way and learning from them. Over the years he has adapted them and now has a brewing recipe of his own that combines different aspects of these traditional beer recipes. First, mashing in some crushed pale malt, then lautering and sparging to obtain the wort, adding treacle and dark brown sugar for colour and flavour in the boil. Sometimes, but not always, porridge oats are added to the mash tun. Hops are used, usually Goldings, Bramling Cross and Fuggles. He's made ancient style ales, when the wort is not boiled, a raw ale. Dried meadowsweet flowers were added for preservation and flavour. The recipe was based upon the analysis of residues on a Bronze Age beaker from Strathallan, Scotland.

Line's recipes reflect the brewing industry of his day. There is no mango puree or other novel additions to his recipes, as craft brewers do today. There are some added sugars, specialty roasted malts and a couple of Line's recipes use malt extract. The transformation of grain into ale is a multi step process: malting, mashing, obtaining a wort and fermenting. It's easily possible to get all the fermentable sugars you need from the malt in the mash tun, when you know how to do it. There is no need for adjuncts or extras in the mash tun unless you want to add them.

The advent of modern craft brewing in the USA in the 1980s has changed the brewing industry. A wide range of innovative adjuncts are now being added to the mash tun. Many people have asked the question: what is craft beer? It seems to be quite a difficult thing to define. Some modern craft brewers use extracts and syrups, adding all sorts of unusual ingredients, such as peaches, mangoes, chillies or chocolate. That's fine. Other craft brewers are all-grain brewers, starting with crushed malted grain in the mash tun and adding their novel extra ingredients to that. That's also fine. The aim is to make good, unusual and innovative beers. Some craft brewers are small businesses, producing their beer for the local market. Others are huge breweries, producing vast amounts of beer for the global market. I'll leave my attempt at defining 'modern craft beer' there. It's a confusing thing.

When I began to investigate the archaeological evidence for beer brewing in the Neolithic and Bronze Age (back in 1996) I started from a practical, scientific and technological point of view. I wanted to understand how beer is made from grain. What's the science behind it? What techniques and skills does the brewer need? The obvious place to start was The Big Book of Brewing. I read the mashing chapter several times and, after that, I went on to study the more complex and detailed work of brewing scientists. My approach was this: if I wanted to recognise and appreciate the evidence for beer brewing in the archaeological record then I needed to understand the fundamentals of the beer brewing process. I was not going to completely rely upon the anthropological or archaeological literature. 

This is something that only an all-grain brewer does. It's the saccharification process. When making malt, enzymes are activated in the steep and on the malting floor. These enzymes, alpha and beta amylase, are kept viable by the maltster during the careful, slow drying process in the kiln. In the mash tun, these same enzymes re-activate and, at the right temperatures, they convert the grain starch into malt sugars. Here's a technical explanation of mashing by David Line in the Big Book of Brewing. I've been to quite a few archaeology conferences over the years, given presentations and said that this is an excellent book if you want to understand how to mash the malt and make a beer from the grain. It usually raises a laugh from the audience. I don't know why.

As mentioned in the previous post, we buy in our malt. We have no facilities to make it. We do our mashing in a modern plastic mash tun, using a grain bag. There are two boilers, one for the hot water which always necessary when beer is being made. You need it for sparging. The other is for boiling the wort. Our mash tun has an electric heater, so we heat the water for the mash in there until it reaches around 74 degrees Centigrade. That's the right temperature for the 'strike' when the crushed malt is added to the hot water. As Dave Line explains above, striking chills the water to 65 degrees Centigrade. Perfect for the enzymes to work.

the strike: crushed malted barley meets hot water

The crushed malt is left in hot water for about an hour. We put a sleeping bag over the mash tun to keep the temperature stable for the starch converting enzymes to get to work. After about an hour, they have done their job and we have a mash tun full of sweetness. The mash is brown, no longer the pale crushed malt we started with. When the lautering and sparging is finished and we have our wort, the grains in the mash tun look as if they are whole. They are not. Only the husks remain. The starchy endosperm has all been converted into malt sugars by the enzymes. This leftover grain is draff, also known as spent grain or brewer's grains and it makes excellent animal fodder. One of the reasons why the archaeological evidence for mashing is minimal.

spent grain, after mashing, lautering and sparging

our mashing experiments and demonstrations
Fire is the obvious way to heat a mash in a sealed earthenware pot, but you have to be careful - too much heat and the saccharification will not work. I made a hearth in our back garden and decided to find out whether I could mash in a pot. Here's a couple of photos of my first mashing experiments. Almost twenty years ago now. This work was done as part of my M.Phil research into the archaeological evidence for brewing in prehistory. I took some crushed pale malt and mixed it with cold water in an earthenware bowl. The porous bowl had been previously sealed with beeswax. I put the bowl on hot ashes to provide a gentle, consistent heat. I decided to start with cold water. The reason being that I could watch over the pot and wait for the correct temperature for the saccharification as the water slowly heated up.

a starchy start to the mashing process

With no thermometer how would I know when the temperature was correct for mashing? This, in practice, turned out to be very easy. The mixture in the bowl began to smell sweet and delicious. The mash changed colour. I tasted it. It tasted sweet. The saccharification was obvious. While I watched the mash pot I made some little 'cakes' or 'biscuits' by making a thick mixture of crushed malt and water. These were put on the flat stone beside the fire. It had become quite hot by now. Splashing water on them occasionally to keep them a bit damp, it was again obvious that sugars were being made. I knew that the enzymes were transforming starch into sugars. I understood the technology and the science. In prehistoric times this transformation of inedible grain into sweetness was, perhaps, deemed to be magic.

saccharification in the bowl and sweet barley cakes on a hot stone

We've done several demonstrations of this 'mashing in a bowl' technique. A couple of times a year we used to work in Hut 7 at Skara Brae, showing visitors that there is more to neolithic grain processing than just making flour, bread, porridge or gruel. Fires are not allowed in the replica hut, for obvious reasons. We overcame this by having a mash we'd made at home earlier. We put it in a bowl on the central hearth, surrounded by samples of modern barley, bere, crushed malt, wort and beer. The mash smelled delicious, people came in to see what was going on. It's much easier to explain the brewing process to people when there are samples available, to smell and to taste. 

The most enjoyable event so far was the one I did at Eindhoven Open Air Archaeology Museum in April, 2009, as part of a small beer brewing meeting organised by EXARC. The mashing was very successful, being caramelised by the end of the day. Visitors to the museum 'stole' some of the sweet biscuits made on hot stones and ate them. Those who tasted the mash said it was delicious. The medieval brewers who had done a demonstration the day before were impressed at our mash in a bowl. 

A caramelised mash in the bowl, sweet barley 'cakes' by the hearth
tub and trough mashing
The shape of the mash tun isn't important. Mika Laitinan explains how Sahti brewers traditionally use both tubs and troughs for mashing and lautering. The ancient tradition of farmhouse brewing in northern Europe still exists in some areas today. Techniques are handed down from one generation to the next. A few years ago I was not aware of this traditional all-grain brewing. I certainly know about it now. I reckon anyone interested in ancient beer brewing should take note of this tradition and study the farmhouse brewing techniques.   

In our experimental work we were inspired by archaeologists Declan Moore and Billy Quinn of the Moore Group, based in Galway, Ireland. They did a trough mashing demonstration at the 8th World Archaeology Conference in Dublin in 2008. I realised that I was simply not making enough mash in my small earthenware bowls. These guys did the job properly. It was a spectacular demonstration of one of the functions of a burnt mound and trough - as a mash tun. Follow this link for more details. 

We've mashed in a wooden tub, using hot stones to heat the water and maintain mash temperature. Below, a couple of photos from the mashing demonstration we did at an Ancient Technology event for the Orkney Archaeology Society, organised by local potter Andrew Appleby in 2010. We heated the water with hot stones, adding crushed malt when we could see our reflection in the hot water. This is an old technique for judging when the water temperature is correct for the strike, before thermometers were invented. It works. We used the hot stones to maintain mash temperature. It all worked perfectly.

heating water with hot stones
the strike

About ten years ago when I was working as a tour guide at Tomb of the Eagles/Liddle Burnt Mound, Orkney, we did a small trough mash for the Orkney Tour Guides Association. The brewer had made a small wooden trough specially for the event. The sweet, delicious aroma of the mash brought people to our demonstration behind the Visitor Centre. They were curious. What was that lovely smell? Some tasted the mash and were surprised how sweet it was. That's the saccharification, we told them, we're making malt sugars. There are more photos of the event here.

mashing in a wooden trough, checking the temperature

The opportunity to mash in a replica stone trough on the island of Bressay, Shetland, in the summer of 2011 was too good to miss. Once again, the hot rock technology worked perfectly, the mash was successful. Before we started we needed to seal the trough with some of the local grey clay to make it watertight. I was a bit worried. Would it adversely affect the brew? Everything was fine. The clay luting had the unexpected effect of making the beer beautifully sparkly and clear. I took lots of photos. They are on my 'Ancient Ale' Facebook page here.

the mash in the stone trough at Bressay, grains have sunk to the bottom, the wort is clear to see. 

a bit on fermentation (as promised) 
Yeast converts sugar into alcohol. There are many different sorts of yeast so it's quite important to get the right one. If not, all that work to obtain a wort will be wasted. There are several ancient options.

In Ancient Egypt it seems that sweet wort was fermented in large pots. Using a scanning electron microscope Dr Delwen Samuel has identified yeast on the internal surfaces of large pots from Amarna, Egypt. Dried yeast inside a pot would work well to start a fermentation and this technique could have been done in any part of the world where pots were used as fermentation vessels.

Another option would be to stir the fresh wort with a stick that had been used to stir the previous ferment. This may sound strange, however, such a practice is recorded in histories of the Western Isles and the Hebrides. The brewer experimented with this technique using a wooden spoon to stir a fermenting brew. He hung the spoon up to dry, then stirred a fresh wort. It worked. Details here.

Yeasts can be cultivated and stored. The traditions of the farmhouse brewers include keeping a dried yeast as a starter. I admit that I am no expert on this. Yeasts and alcoholic fermentation is such a huge subject and I tend to focus on the malting and mashing parts of the brewing process. The world of all-grain brewing, as well as yeast specialists, have recently been amazed at these farmhouse yeasts from northern Europe. The place to read about them is here, where Lars Garshol explains about some of his extensive work on researching and discovering the farmhouse yeasts and ales.

Lambic beers are famous all over the world. The wort starts to ferment because there are wild yeasts and bacteria within the brewery. The resulting beers are aged for several years and are often sour, so fruits can be added to sweeten the brew. Here's a short definition of lambic beers, more information here.

"Belgian Lambic beer is left in open vats where wild yeast and bacteria are encouraged to take up residence. In fact yeast is never added directly to the wort. Instead wild yeast that is unique to the region is simply allowed to fall into the vats in a process known as spontaneous fermentation."

Finally, a word about spontaneous fermentation. I was once told that it's possible to ferment a beer by 'brewing under a tree'. Some people think you can just leave the wort to 'catch a wild yeast'. Be very careful if you do this.

You might catch the wrong one.


  • A bit more on fermentation - there are very many kinds of fermentation and most of them are not alcohol producing. Think of sauerkraut, yoghurt, food preservation etc. It's a huge topic. See Steinkraus: Handbook of Indigenous Fermented Foods if you have access to a University Library. It's an expensive book and a thorough study of the subject. If you don't have the luck to get into a University Library, then there's this paper available online 'Fermentations in World Food Processing' also by Professor K.H. Steinkraus. 

  • More on brewing techniques - you might like to read this post on farmhouse brewing by Lars Garshol. There are some very clear descriptions of the brewing process and great photos to show how beer brewing has been done for generations in Estonia. As they say, a picture speaks a thousand words.

  • Could the Natufians, the earliest agriculturalists of the Fertile Crescent over ten thousand years ago, have made malt and ale? Did they have the technology? Thomas Kavanagh (1994) discussed this in Brewing Techniques magazine. "Archaeological Parameters for the Beginnings of Beer" 

  • Finally, my published research papers and my M.Phil Thesis (2004) can be found on Researchgate and downloaded for free. 


Friday, 23 February 2018

malting and mashing

Today is a brew day. The brewer has just come into the house from our garage/brewhouse with a small glass of delicious sweet liquid. He's just finished mashing in, he's half way through the sparge and is sampling the wort. This one is particularly sweet, malty and it's very good. The malt was fresh, the mashing in went well and the next stage will be boiling the wort with a variety of hops. Then there is the last stage, fermentation. This is all-grain brewing, which I know of as 'brewing with grain'. It's a brewing style rather than a specific recipe, list of ingredients or grain bill. The Brew Your Own magazine defines it like this:

All-grain brewing differs from extract brewing mainly in the wort production stage. As an extract brewer, you made your wort by dissolving malt extract in water, and likely steeping some specialty grains to add some additional flavours. As an all-grain brewer, you will make your wort from malted grains and water. The basic idea behind all-grain wort production is this:
You soak crushed, malted grains in hot water to change starch into sugar, then drain away the resulting sugary liquid, which is your wort.

Here's a couple of photos, of the runnings from the mash tun and the lovely, sweet wort that I was given to taste.

Brewing beer from the grain is an ancient technique, probably going back into prehistory, with the first maltsters and brewers of the Fertile Crescent some ten or maybe twelve thousand years ago. Local herbs and plants were used as flavourings and preservatives instead of hops, of course, but this is the way that the wort for ale and beer has been traditionally made. You need sugars to ferment into alcohol and this is a two step process.

Malting and mashing are fundamental aspects of the beer brewing process. These are the processes that have, for millennia, transformed starchy harvested grain into sweet wort that is fermented into ale and beer.

making the malt
It's not practical for us to make our own malt at home. We just don't have the facilities. I suppose I could steep some grain in a very large bucket, changing the water every four to six hours, thus giving the grain its necessary air rests. But there's no space in my home for a malting floor. I'm looking with interest at some of the traditional Norwegian farmhouse malting techniques that involve germinating the grain in wooden trays or boxes in the sauna building. No need for a germinating floor. Beer historians Mika Laitinen and Lars Garshol have visited, worked with and interviewed brewers who still make their own malts. If you want to know more about this and see some fabulous images of the buildings and necessary equipment then follow the links above.

I've learned from Lars and Mika that you don't need a malting floor to make household quantities of malt for ale and beer brewing. However, the malt must be very carefully dried, and that's something that needs a lot of serious consideration and planning. As I explained in the previous post, a base malt is not roasted or toasted. High temperatures destroy the starch converting enzymes. A base malt is dried with care, without overheating, so that the enzymes within the partially germinated grain remain viable. They reactivate in the mash tun where they will convert all of the grain starch into fermentable malt sugars.

Instead of making our own malt at home we order a sack from an online supplier. It arrives fresh, having been crushed within the previous couple of days and sent by courier. Freshly crushed malt makes good beer. Stale malt is not so good. When we lived in a city we ordered a 25kg sack of base malt from the local homebrew shop, collecting it ourselves.

The malt that we buy is made in a modern germinating kilning vessel (GKV) where the grain is steeped, air rested and dried, all in the same enormous vessel. The germination process within the grains remains the same as if it had been malted using traditional methods, such as floor malting. Some argue that there is a difference in flavour between floor malted grain and that made in a GKV. I don't know about that. You might be wondering, where did all these traditional malting floors go? I do know a little about that story and wrote a post about it a while ago. The good news is that traditional floor malting is making a comeback. 

what happens inside the grain as it germinates?
This is, for me, the magic of the malt. The biochemistry and physiology of germination were not understood until the 1960s. Yet maltsters have been making good malt for thousands of years. The technology has developed. Maltsters knew exactly what they had to do in order to keep the spirit of the grain alive. Take a look at the book on Malt and Malting by Henry Stopes (1885) if you want to read about the traditional technologies that were involved prior to a biochemical understanding of the germination process. No need to buy it. It's been scanned in, with illustrations. A fabulous resource for the study of traditional and historic malting technologies.

Below is a section through a barley grain as it begins to germinate. It shows the structure of the grain and some of the chemical changes that occur within it that enable growth. In the steeping process, the grain absorbs water and oxygen, both are necessary for germination to begin. The embryo (scutellum) releases a growth hormone, gibberellin, that stimulates the aleurone layer to release enzymes that convert starch into sugars, the food source for the growing plant. The aleurone layer is a single layer of cells beneath the husk. There are other biochemical changes within the grain, for example, some enzymes break down the husk making it easier to crush.

first stages of grain germination
see Bewley and Black Seeds and physiology of germination for the original diagram.

The second image, below, shows what happens when the grain is on the germination floor. Enzymes convert some of the starchy endosperm into malt sugars. The technical term for this part of the process is modification. You can see that the endosperm has been wholly modified (wm), mostly modified (mm), partially modified (pm) and unmodified (um) at this stage. When rootlets show the grain is ready for drying. If the maltster is lucky, they live in a hot, sunny climate where the malt can be dried in the sun, as described in the Hymn to Ninkasi. Otherwise, the malt is dried in a kiln with warm air, and sometimes smoke, passing through the bed of grain. Drying malt takes several days.

on the germination floor
see Bewley and Black Seeds and physiology of germination for the original diagram

The biochemistry and physiology of grain germination is now one of the most studied aspects of barley, wheat and rye. All of these grains can be malted. I know that what I've written here is just a fairly basic explanation of grain germination. I've tried to keep it simple. If you want to know more, read Bewley and Black, or read some of the more recent papers by a wide range of scholars, many of which can be found on the internet.

what happens in the mash tun?
The mash tun is where the sugars are made. Many different vessels can be used as a mash tun. If the vessel is made of wood then you must use hot stones to heat the mash. If not, then you can use fire. For the brewer, 'mashing in' is not like mashing grapes or mashing potatoes. It's more like mashing tea, perhaps. The crushed malt is left in hot water for about an hour. The enzymes need time to work. And the temperature needs to be right. Below 60 degrees Centigrade the conversion is so slow that you risk infection.     

When crushed malt is mixed with water, then heated to around 67 degrees centigrade the enzymes within the grain reactivate and convert all grain starch into fermentable sugar. It usually takes about an hour for this enzymatic process to be completed. As the enzymes get to work, the aroma is sweet and delicious. You know whether or not it's working. The mash becomes sweeter. Knowledge, practice, experience and skill are all a part of the process.

The photograph below was taken at the Eindhoven Open Air Museum where I did a mashing demonstration several years ago.

I like this photo because you can see pale crushed malt in the two pots beside the hearth. The wonderful ceramic bowl on the fire was made by Flor Buchuk Gil. She was working as the potter at the Museum and, very generously, she gave me this pot to use on the day and to take home. I had some fun getting it on the aeroplane, but that's another story. In this bowl you can see the dark brown mash. Sugars have been made. I've written about it in an earlier post, the process is called saccharification. For this mashing in demonstration, I had mixed some of the crushed pale malt with water, then heated it by surrounding the bowl with charcoal. I wanted a gentle heat. It was a very good conversion.

The next stage of the brewing process is to separate the sweet liquid from the grain. More sugars can be washed out of the mash by running hot water through it and collecting the run off. The sweet liquid is called wort and this is what can be fermented into alcohol. No need to add anything. All the sugars for fermentation have come from the grain.