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 saurkraut, 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

Finally, all of 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.

Monday, 22 January 2018

roasted toasted sprouted barley

Until the Industrial Revolution there was only one kind of malt. So we were told by maltsters at the seminar we attended a couple of years ago. It had been organised by the Orkney Science Festival and was held at the Highland Park Distillery. Only twelve tickets available, so we were very lucky to be there!

Malt has been made using the ancient and traditional techniques of steeping, aeration and floor malting for thousands of years. Grains such as wheat, barley, rye, millet or oats can be malted. Making malt was probably one of the first grain processing techniques, going right back to the earliest grain agriculturalists of the Fertile Crescent, at least ten thousand years ago and maybe more. What is floor malting? Harvested grain is steeped and aerated before being partially germinated. Most importantly, drying the green malt must be done very slowly and carefully. This is how a base malt, known also as diastatic malt today, has been made for generations upon generations. 

This kind of malt is not roasted or toasted at high temperatures.

Why not? Because roasting the malt at too high a temperature destroys the enzymes within the germinating grain. These enzymes are essential to convert starch into sugars later in the brewing process, that is, in the mash tun. Although the scientific explanations of grain germination, the biochemistry and the physiology, have only been understood since the 1960s, maltsters have known the importance of keeping the 'spirit of the grain' alive throughout the malting process. From steeping to kilning, maltsters have known what to do for a very long time. Henry Stopes' classic study of the practices, processes and technicalities involved in making good malt and malting technology (published in 1885) is a book that I repeatedly refer to. In his first chapter there are several descriptions of how malt was made in medieval times and earlier. I especially like this one, where it is clear that the early maltsters definitely knew how to handle the germinating grains:

"the grain was steeped and germinated, by which its spirits were excited and set free; it was then dried and ground and infused in water, when after [it was] fermented."
by Geoponius? cited in Henry's History of England, see Stopes (1885)  

To make good diastatic or base malt you have to do the right things in the right way, using suitable temperatures and having the correct conditions for each stage of the process. Making malt is a craft. It requires specialist knowledge, skill and experience. There's a lot more to it than just sprouting a few barley grains in a jar in the cupboard under the sink, or in a warm place. The maltster's knowledge, experience and skill means that they can steep, aerate and partially germinate very large quantities of grain without it going mouldy or bad.

Modern specialty malts, such as crystal malts, amber malts and chocolate malts are roasted at high temperatures, but these only began to be made around the 17th/18th century. They are a modern technology, used to add colour and flavour to beer. They do not provide fermentable sugars. Roasted, toasted specialty malts came about because of a change in the fuel used to dry the malt. The Industrial Revolution introduced a new fuel: coke. Practices changed from using from wood or straw to dry the malt to using coke, the result being a paler malt than was previously produced.

So, to cut a very long and complex story short, malts began to be roasted and toasted at around the time of the Industrial Revolution in order to make ale and beer the colour that consumers were accustomed to. Specialty roasted, toasted malts are not a technology of the Neolithic, Bronze Age, Iron Age, Viking or Medieval eras.

What has any of this to do with archaeology or archaeobotany?

Well, I've just read yet another paper where the archaeobotanical report incorrectly uses the terms toasted or roasted sprouted barley when considering that the carbonised cereal grains and fragments of grains discovered there could have been malt for brewing purposes. This paper was published in the specialist archaeobotanical journal Vegetation History and Archaeobotany in December 2017. So there is little chance of it being read by a maltster. It's well worth reading because this is some of the best evidence yet discovered for malting. It is a shame that the descriptions of how to make malt, how to mash and ferment into beer are misleading and confused. More on that later. It's possible to contact the author and get a copy. That's what I did. Here's an extract from the abstract:

"Archaeobotanical remains of sprouted cereal grains as well as cereal fragments from the Bronze Age sites of Archondiko and Argissa on mainland Greece, presented here for the first time, provide strong indications for the making of something similar to beer in late 3rd millennium BC Greece, opening up a series of new questions about the recipes followed in this process and their origins."

What about those words sprouted cereal grains? To many people, they suggest growing long bean sprouts, the sort of thing we grew in school in Biology lessons, but that is not what malt is. Malt is grain that has only just begun to grow. The acrospire should be about three quarters of the length of the kernel or perhaps a little bit more. Too much growth and all of the grain starch will be used up and there will be nothing for the mash tun.

This kind of description of malt as toasted roasted barley sprouts has been repeated over and over again in the archaeological and archaeobotanical literature, in excavation reports and elsewhere. The idea that to make malt for beer brewing in prehistory, the grain was sprouted and then roasted or toasted in a very hot kiln is incorrect. However it's a very common explanation. It doesn't seem to be tied to any particular era, I've read papers and excavation reports that discuss sites from the Neolithic to the Iron Age and beyond. They usually say, that is, if malt is even acknowledged as being part of the beer brewing process, that the grain was sprouted and then roasted or toasted to make malt.

In the article on Booze! in National Geographic magazine (February 2017) brewer's malt is described by the journalist, Andrew Curry as sprouted toasted barley grains. Not being a malting or brewing expert himself, he has clearly relied upon information given to him from brewers, such as Martin Zarnkow who he interviewed for this article. Zarnkow has attempted to recreate Sumerian beer on the laboratory bench using malt mixed with unmalted grain and using sourdough as a starter for fermentation. He claims he can make alcohol overnight. It is a strange recipe for beer. 

Incidentally, there are some rather odd recipes for ancient beer around. For example, Professor Patrick McGovern's most recent book, Ancient Brews, uses malt extract (a Victorian invention), specialty malts and other unusual ingredients for an ancient ale. When he was recently interviewed by Beersmith, the Professor acknowledges that he has never actually made a beer from the grain and that perhaps he should try it, for the experience. I'm wondering, how can he be a beer expert when he has no experience of making beer from the grain?

Ancient ale and beer recipes are the subject of another blog, not yet finished and not yet published.

The main point that I want to make in this post is that roasted toasted sprouted barley is not a suitable description of malt, malting or malting technology prior to the 17th/18th centuries AD. It's wrong. Archaeologists and archaeobotanists should read beyond their own literature. They should talk to maltsters and read about malting and brewing science if they want to understand what malt is, how it has been traditionally made and what its' properties are. It's a fascinating subject.


 some further notes ...

Although no comments have been posted, I've had some quiet, private and useful feedback from a few people. It seems that those who have no personal experience of making malt or brewing beer from the grain find it very difficult to understand these processes. Some struggle to see, in their mind's eye, how this so-called 'sprouted' barley can be transformed into ale. What happens to it? How is it processed?

I've been told that this film is helpful:

About 30 minutes long, it was made in Norway in the 1960s. The equipment used would have been available in the Viking and Medieval eras, probably also in the Iron Age. It shows some of the traditional, farmhouse brewing techniques. Also, it gives you an idea of how to handle the necessary quantities of grain that must be malted before being mashed and then fermented into ale. 

There is great skill, knowledge and experience involved in making good malt and brewing ale with it. You can get all the sugars you need to ferment into beer from the grain. There is no need to add extra sugars or honey. 

I hope it helps! 

Monday, 1 January 2018

some sort of alcohol

Stonehenge at midwinter - a time for feasts source

Midwinter. It's a good time to think about feasts, festivals and family gatherings.

Seasonal celebrations at the turn of the year are a long-standing tradition, whether your new year starts with the Midwinter Solstice, as mine does, or whether you prefer New Year's Eve at midnight on December 31st. Most archaeologists and anthropologists would agree that feasts have been an important and significant part of life in the past. People have been feasting together for thousands of years. Anthropologist Brian Hayden has asked Why do people feast? He reckons that in the past feasts were important as a display of power and strength. They also played a role in social support networks. It all makes good common sense. Recent discoveries at Hilazon Tachtit seem to suggest that ritual feasting coincided with the earliest agriculturalists of the Ancient Near East. These people were gathering and processing the wild cereal grains, such as wheat and barley.

"Twelve thousand years ago humans were still hunter-gatherers, subsisting entirely on wild foods. Nevertheless, these people differed from those who went before – they were sitting on the brink of the transition to agriculture, one of the most significant economic, social and ideological transformations in human history.  Sickle blades and grinding stones used to harvest and process cereal grains are found at Hilazon Tachtit and other contemporary archaeological sites. These findings indicate that these ritual feasts started around the same time that people adopted agriculture. When people began to rely more heavily on wild cereals like wheat and barley, they became increasingly tethered to landscapes that were ever more crowded and began to settle into more permanent communities. In other words, feasting became a part of their life, once they moved away from nomadic life."

What were they doing with the grain?

We know that people were drinking some sort of alcohol at these ancient feasts. Maybe it was not an obligatory thing. Perhaps there were some non alcoholic beverages also available. It is, however, generally agreed and understood that some sort of alcohol was made and consumed. Most of the discussion in the anthropological and archaeological literature focuses on the significance of drinking alcohol and its' social aspects. There's not much on the technicalities and details of how they made it.

That's the bit that interests me. How did they make it? What were the ingredients?

Most importantly, what was the recipe, what were the techniques and what equipment was used?

Different sorts of alcohol have been and are consumed all over the world. If you want an easy-to-read summary of recent academic ideas about alcohol and feasting in the past, have a look at Booze! in the February 2017 issue of National Geographic magazine. This article is a brief overview of current thinking and ongoing research into ancient alcohol. It covers a lot of ground, from rice wine in China to ancient Sumerian beer as well as chicha and grape juice. The underlying premise is that

"alcohol isn't just a mind altering drink:it has been a prime mover of human culture from the beginning, fueling the development of arts, language and religion" 

I'd agree with that. 

But there are some things in this National Geographic article that I don't agree with. Some inaccuracies about malt. There's that often made mistake about what ancient malt was. Here it is described as 'sprouted toasted barley grain' and this seems to be a standard description of ancient malt in much of the archaeological and anthropological literature. 

Malt is frequently described as toasted roasted sprouted grain. This is true only of modern specialty malts which have been germinated, then roasted at high temperatures. Specialty malts include amber malts, crystal malts and chocolate malts. They date from the Industrial Revolution, not the Neolithic Revolution. Maltsters began to make the specialty roasted malts when coke supplanted the traditional straw or wood as the fuel for drying malt. Why? Because the new coke-dried pale malt did not give the colour to the beer that everyone was accustomed to. That is a huge story in itself.

The main kind of malt that has been made for thousands of years is base malt, the one that provides all of the fermentable sugars in the mash tun. Base malt must be dried very carefully in order to keep the spirit of the grain alive. We now understand the science involved in the partial germination of grain, that this careful and slow drying of the malt preserves enzymes that convert starch into sugar. Maltsters have known how to do this for generations, as described in Henry Stopes' book, Malt and Malting (1885).

What were they drinking at feasts in Neolithic Britain?
Recently I spoke to a pottery specialist, one of the archaeologists at the Ness of Brodgar, an important Neolithic ceremonial site on the mainland of Orkney. I asked this question. What were they drinking at the feasts? I was told that, of course we know they were drinking some sort of alcohol. And with that, there was an end to further discussion. They walked away. Although there is a lot written about this fabulous excavation on the internet, they do not seem to be addressing the issue of what sort of alcohol they may have been drinking at the feasts and celebrations that they say took place regularly at this place, 5000 years ago.

I've been reading the promotional and educational material from the latest exhibition at the Stonehenge Visitor Centre. It's called Feast! But sadly, for some reason, they have also decided to ignore the question of what sort of alcohol they were making and drinking at Durrington Walls in Neolithic Britain. The exhibition Feast! deals only with the food aspect of feasting. With minimal evidence for cereal processing found during excavations, they say that porridge was made. They even mention, in the publicity material, that the neolithic folk were feeding their pigs with honey to fatten them up. This, apparently, explains the archaeological discovery of caried pig teeth at Durrington Walls. Feeding the pigs spent grain is a far more likely reason.

for more about this photo see here: English Heritage

Making malt and ale are not considered as possibilities in this Stonehenge exhibition. Nor is it considered in interpretations at the Ness of Brodgar, Orkney.

I don't understand why. There is so much in the academic literature about the importance of the consumption of alcoholic beverages in past societies, particularly at feasts, celebrations and communal gatherings.

There was only one suitable source of fermentable sugars plentiful enough to provide feast grade alcohol for large gatherings at these neolithic feasts. That was the cereal grain that they grew. Barley and wheat can easily be transformed into sugars for fermentation into ale by the straightforward processes of malting and mashing.

Cereals are usually considered to have been a staple crop in the Neolithic. They are more likely to have been a status crop, for their potential to be made into malt sugars, wort and ale.


Interested in ancient malt and ale? Our published papers and my thesis "Barley Malt and Ale in the Neolithic" (2004) can be read and downloaded from my new Researchgate page. see here

Friday, 30 December 2016

alcohol production

There is a debate in the academic literature of archaeology and anthropology about alcohol production, the archaeology of alcohol and the consumption of alcoholic beverages in the past. It seems to be an increasingly popular area of study. Search the internet using these phrases and you will find plenty of books, papers and articles. Unless you have access to a University library, however, many of them are not easily accessible. They are behind pay walls.

The phrase 'alcohol production' neatly avoids the science, biochemistry and technology behind a number of varied and differing processes for making alcoholic drinks.

This generalised idea of 'alcohol production' is about as sensible and informative to understanding the processes as talking about 'metal production'. Different kinds of metal obviously require specific methods of production. Copper, bronze and iron are produced in very different ways. It's the same with making different kinds of alcohol from different sources of sugars.

No-one would ever believe that a primitive kind of weak metal could be produced by accidentally leaving some coloured rocks in a fire overnight. However, the story goes that a primitive sort of beer was discovered when a container of grain was left outside, it rained, the grain got wet, it germinated then it fermented and made some sort of weak beer. Or, maybe, a loaf of bread fell into a bucket of water, then it fermented. This simply cannot happen, it would defy all the laws of biochemistry.

One aspect of this 'alcohol production' debate is that grain can somehow naturally ferment into a weak beer when immersed in water. We have been told by a number of archaeologists that to make a primitive beer you don't even need malt and that barley can naturally ferment. This is scientifically and technically impossible. The idea of natural fermentation was first presented in this paper dating from 1991 and many subsequent academic papers cite this as evidence.

It is one of the myriad of anecdotal myths about alcohol, for example that animals can get drunk by eating rotten fruit. We shall write more about this sort of thing in future posts.

Grain is a living thing. When left in a bucket of water the grain drowns, it goes bad. Grain requires both water and oxygen to begin germination. For details of steeping the grain in a bubbling stream see an earlier post about how to make a base malt.

The idea that early beers or ales were somehow weak and inferior is also fallacious. If it were weak it would then be useless for that 'altered state of consciousness' that was, according to the academic literature, necessary for social feasting or ceremonial occasions. In Britain any alcoholic drink of less that 1.2% is not considered to be intoxicating, and is not subject to any Excise tax laws or regulations. Beer of less that 2.8% alcohol is classed as 'small beer", and is subjected to a low tax, whilst beers above 7.5% have a higher tax. Beer can be made to any strength the brewer wants.

Alcohol is produced by yeast when it digests sugars in the absence of oxygen. In the presence of oxygen, however, the yeast will produce water and carbon dioxide but no alcohol. You need anaerobic conditions for alcoholic fermentation. Yeast cannot ferment starches, only sugars. Sugar ferments into alcohol. Cereals do not contain any sugars. Therefore, it is absolutely impossible to make alcohol from grain by natural fermentation.

The concept of 'alcohol production' should be replaced by 'sugars production'. This would be a revolutionary paradigm shift in archaeological theory. Cereals can be easily converted into sugars when you have the right knowledge and skills.

Cereals are not just a staple crop, they can also be considered a status crop.

Grain can be converted into sugars by first malting it. Malt is partially germinated grain, it has the necessary enzymes, alpha and beta amylase, to convert starches into sugars in the presence of water. This occurs most rapidly when hot, at around 65 degrees Centigrade. The water is not only a suitable medium but it's also a necessary part of the biochemical reaction, hydrolysis. This is the mashing or saccharification process.

What, exactly, is malt? There is very little discussion of malt and malting technologies in the archaeological and anthropological literature. What is written appears to derive entirely from scholarly works written by archaeologists and anthropologists. There is no input from maltsters or brewers who actually work with malt. The archaeological and anthropological literature is self referential and frequently wrong. For example, malt is sometimes described as 'toasted, roasted, sprouted grain' which is not an accurate description of a base malt that provides the fermentable sugars in the mash tun.

When you roast the malt at hight temperatures then you destroy the enzymes and there will be no sugars to ferment into beer. Roasted malts are a modern phenomenon, dating from the around the 16th and 17th Centuries AD. There is an incorrect description of making malt for brewing by roasting it in a kiln in this paper.

Malting and the production of of liquid malt sugars is probably one of the first, if not the first, cereal processing technology. It's far easier to wet process the primitive grains that have more husk than starchy endosperm into desirable malt sugars than it is to grind them into good flour to make bread. To make porridge or gruel, the grains must be boiled for hours.

Malting and the production of liquid malt sugars from the grain was widespread throughout the Fertile Crescent, the cradle of agriculture, long before the rise of Islam. There is good evidence for deliberately made malting floors of stamped earth, clay and even of lime plaster at some of the first agricultural settlements of the Ancient Near East, for example at Beidha. Today the production and consumption of alcohol is forbidden by Islamic law. The civilisations of Ancient Egypt and Mesopotamia are well known for their beer manufacture. Now people no longer make malt in these countries.

There is a Biblical expression that describes "... a land flowing with milk and honey". Nobody thinks that this phrase refers to milk actually flowing through the fields. It is more likely to be a reference to rich grazing land that feeds the cattle, goats and sheep. The reference to honey seems to confuse the scholars. The Hebrew word debash or d'vash that is used in the Bible does not mean 'bee's honey' but, rather, it refers to an artificial sweetness of a vegetable nature, which scholars interpret as being made from dates, figs or possibly even grapes. To a brewer this is obviously wort, the liquid malt sugars. So the phrase 'land flowing with milk and honey' is a metaphor for rich pasture and arable land.

It's obvious that none of these scholars or archaeological experts have ever tasted sweet wort, straight from the mash tun. When we do mashing demonstrations we have invited people to taste the wort. Archaeologists have been known to refuse, sometimes backing away from us as if wort is somehow poisonous or horrid. No thanks, it's ok, they say. Those who do taste it usually say that it is sweet and delicious, commenting that it tastes like that stuff you get in jars for the vitamins. What they mean is, it tastes like malt extract, which is just concentrated wort.

Archaeologists Declan Moore and Billy Quinn came to Orkney ten years ago to have a look at our mash tun and brewing facilities. They both tasted the wort and were surprised, declaring it to be sweet and tasty. They were inspired enough to go and make some beer for themselves, in a spectacular way. They used a wooden trough and some hot rocks to re create a Bronze Age beer.

When brewers looks at a field of barley they see the potential for making malt for barrels of ale, beer or whiskey. Other people might see a field of grain to be used for making flour, loaves of bread, porridge or gruel. 

There are many malts and they can be rather confusing. There's brown malt, pale malt, barley malt, wheat malt, oat malt, millet malt, crystal malt, roasted malt, chocolate malt, amber malt, single malt, three year old malt and thirty year old malt. It's a huge list.

The last three are whiskeys made from barley that has been malted then mashed, with the wash from the mash tun (brewers call it wort) fermented and distilled. They have nothing to do with the case other than malt being the source of the sugars for fermentation. The first six are diastatic base malts, with enzymes, and with the power to convert starch into sugars. The four middle ones are modern specialty malts with no active enzymes. They have been roasted at high temperatures and this destroys the enzymes. These malts are decorative, used strictly for the colouring and flavouring of ale and beer.

The enzymatic power of malt is measured by obscure units, the Diastatic Conversion Coefficient. Modern barley malts can have a DCC of about 200 degrees, some might even have as much as 230 degrees. Around 37-40 degrees of DCC is considered sufficient for self conversion. That's to say, a grain only needs this amount of enzymes to convert all of its' starches into sugars. Early malts need not have had all their grains successfully or completely malted to effect a good conversion into sugars.

In the 1970s some archaeologists at the Butser Farm made some malt using their recreated 'heated malting floor'. They achieved only two degrees of DCC. Although they were pleased with their amber malt, what they had made was a specialty malt, not a base malt. It was not useful for providing the sugars to ferment into alcohol.

This excess DCC power of modern malts can be used in the production of sugars. One traditional recipe for potato vodka or potcheen is one part crushed pale malt, by weight, to five parts boiled potatoes. The excess enzymes convert the potato starch into fermentable sugars. 

It seems clear to us that, given the confusion and misunderstanding in the archaeological and anthropological literature about malt, what it is and how it is made and used, it's time that archaeologists and anthropologists started talking to the practitioners of the crafts of making malt and brewing beer.

The photograph below shows one of our demonstrations of the mashing or saccharification process. It was taken at the Eindhoven Open Air Museum a few years ago. We took some crushed malted barley, heated it in with water over the warm ashes of a fire made from wood and charcoal. Within one hour, the enzymes in the malt had converted all the starch into sugars.

This saccharification process works in a bowl and it also works on a hot flat stone beside the fire, provided that you keep the malted barley biscuit/cake wet all the time. You don't even need a container to mash.

The sweet bappir or 'cakes' on the stone were eaten very quickly, taken by visitors. In prehistoric times, the manufacture of malt sugars from the grain, by malting and mashing, would have been equally as desirable.

a demonstration of the mashing or saccharification process, using basic equipment 

We welcome comments and discussion, in fact, we look forward to them.