what's the archaeological evidence for malt?

This is something that I became more and more interested in, once I had completed and submitted my thesis. How does an archaeologist or an archaeobotanist recognise whether or not a grain is malted? What happens inside the grain on the malting floor? I had access to the University Library for a few years after my degree - by teaching archaeology classes in the Continuing Education Department. I explored sections of the Library that, perhaps, no archaeologist had visited before. I studied grain germination physiology, biochemistry and discovered that Bewley and Black's classic study of seed germination was the best.

Malting is an important craft and technology. The main reason for making malt is to brew with it, or more specifically, to make an ale or beer from the wort. Malt is also the main ingredient for whiskey, of course, but I am most interested in malt and ale in prehistory and its' role in the origin of grain agriculture. Apart from grain barns and malting floors, it seems that the best archaeological evidence for malt lies within the grain itself. There are clear physiological indications, depending upon whether the grain is desiccated (dried) or carbonised (charred).

Carbonised or charred grains are frequently found in archaeological excavations from the neolithic, when people first began to cultivate and process grain, right through to the medieval era and beyond. Carbonised grains are found all over northern Europe.

What do they signify?

Is it evidence of a grain store or granary that has been destroyed by fire? This was suggested in interpretations of excavations of an huge rectangular timber building at Balbridie, Fife, Scotland where thousands of carbonised grains were found?

Perhaps the grain dryer in a barn caught fire, while they were drying the harvested grain or oats. Or was it a kilning of the malt, which has gone disastrously wrong?

Lots of grain barns have burned down over the years, as well as traditional malthouses. It's not an unusual event. Even in recent times, as late as the 1960s, malthouses have been known to catch fire.

Carbonised grains were found at Eberdingen-Hochdorf, where there were the remains of Iron Age malting and brewing. This Iron Age site was excavated by Professor Hans Peter Stika between 1989 and 1993. According to the excavation report, it was a high status site, probably the rural residence of a prince. The carbonised grains, a huge number of them, were found in a sort of U shaped ditch, together with bits of charred wood. The interpretation was that as the malt was being dried, the fire had got out of control and set fire to both the wooden platform upon which the malt had been laid, as well as carbonising all the malt. The charred grains were mostly barley. Many of them had missing embryos and the grain was in poor condition.

They were identified as having been deliberately malted using these criteria:
... groove like channels on the dorsal sides
... the dorsal side becomes concave
... the coleoptile and coleorhizae become more prominent
... germination roots develop
... separated or fragmented embryos
... germination was even, meaning that it was deliberate and intentional

A recent excavation at another Iron Age site has also identified the activities of making malt and brewing by examining the charred grain. Another accidental fire had preserved the malt as it was being dried in the 5th Century BC at Roquepertuse in south eastern France. The sample of grain was taken from the floor of a building, close to a hearth and an oven. The excavators describe it like this:

"In spite of favourable conditions for the preservation of seeds in the sediment, which was rich in ash, charcoal and generally carbonised plant material, the grains are corroded and highly fragmented. This fairly poor preservation seems rather specific to the barley grains from this sample. Conditions are therefore not suitable for a satisfactory observation of all the morphological features of most of the grains. However, the best preserved specimens allow the assessment that slightly more than 90% of the grains were sprouted when carbonised. This is easily visible from the groove like channel on the dorsal side of the grains. As far as we can see, the sprout length is not perfectly uniform, but it generally reaches about two thirds the length of the grain. 

The poor preservation of barley grains is probably caused by germination, which tended to render them brittle. Fragmentation occurred mostly after carbonisation and is therefore not due to Iron Age human practices." Bouby et al, 2011, Never mind the bottle. Archaeobotanical evidence for beer brewing in Mediterranean France and the consumption of alcoholic beverages during the 5th Century BC

It's beginning to get a little bit technical here and, perhaps, a good time to explain some of the grain germination jargon. There is a lot of it, so I shall stick to the basics. The fundamental biochemical processes and the physiological changes of grain germination occurred in ancient grains just as they do today, in modern grains. It doesn't matter whether you make malt 10,000 years ago or 5000 years ago or 10 minutes ago, the biochemistry of grain germination remains the same.

Grains are a lot plumper than they used to be, because of selection and development by farmers over the millennia. The aleurone layer, a special layer of cells just beneath the husk, is three or four cells in depth in modern grains, rather than the one or two cells in ancient grains. The structure of ancient cereal grains was studied by Professor Geoffrey Palmer, who looked at 3000 year old grain from Amarna, Egypt. Using a scanning electron microscope to investigate ancient desiccated grains, he found that the internal structure remained intact. Individual starch granules within the endosperm could be seen with little holes or pits, where the enzymes had begun to convert grain starch into sugars. There are lots of wonderful scanning electron microscope images in his paper.

Carbonised, or charred grain is found on many archaeological sites in Northern Europe and the British Isles. The matrix of charred or carbonised grain has been destroyed by heat of the fire, so it is not possible to look at individual starch granules. Although carbonised grain is often used just to provide a radiocarbon date for the site, there might be other clues for the archaeologist and archaeobotanist that reveal what kind of grain processing techniques were taking place. Such as separated embryos, fragmentation and friability.

what happens on the malting floor?
Barley, wheat, oats, sorghum and rye can all be malted. I hope these diagrams of grain and malt will help to explain how the grain germinates. This is how it works at a basic level.

When the grain has been sufficiently steeped and aerated in water, growth hormones (gibberellin) are activated in the scutellum and embryo. These growth hormones stimulate the production of enzymes in the aleurone layer, which is a thin layer of special cells, just beneath the husk.


The maltster knows, through skill and experience, when the grain is sufficiently steeped. The wet grain is transferred to the malting floor, where it is piled up, then gradually raked out into a bed, a few inches deep. Here it begins to germinate. When rootlet and shoot are about one third the length of the grain, it is called green malt, and the next stage is to carefully dry it. 

Biochemical changes occur within the grain as it germinates on the floor. The enzymes that were activated within the aleurone layer begin to convert grain starch into sugars, the initial food source for the growing grain. These are the same enzymes that re activate in the mash tun and make a sweet mash. Other enzymes break down the husk, making the grain friable and, therefore, easier to crush than unmalted grain.

Malt, therefore, is made up of mostly starch, with a few sugars and, most importantly, those dormant starch converting enzymes that re activate in the mash tun at the right temperature.

Grain germination has a complex biochemistry. Scientists still don't fully understand how the aleurone layer works. If you want to know more detail, have a look here. If you want to read even more detail, have a look here, at chapter 14 of 'Barley: production, improvement and uses' by Steven Ullrich. Or get hold of a copy of Bewley and Black.

The products of brewing are ephemeral. Malt goes into the mash tun. Wort is fermented into ale which people drink and spent grain is fed to animals and waste liquid is washed down the drains. For the maltster and the brewer, it is a tragedy if the grain barn is destroyed by fire while the malt is being dried. For the archaeologist and archaeobotanist, it is a wonderful thing because the grain is carbonised and it is therefore preserved for analysis.

drying the green malt
Straight off the malting floor, it is called green malt. The maltster stops the growing process by gently drying the malt in a kiln. Gentle heat does not destroy the enzymes. Warm air passes through the malt, usually over several days. Traditional grain drying kilns do not have a solid floor. The malt is put upon a permeable floor to dry, so that warm air passes through the grain bed. Making good malt is a skilful task.

Today, maltsters produce a variety of types of malt by kilning at different temperatures. Base malts are kilned at lower temperatures. The enzymes are not destroyed and will remain active in the mash tun. Specialty malts are kilned at higher temperatures, destroying the enzymes. These provide only colour and flavour to the beer, making up no more than 10% of the grain bill in the mash tun. Specialty malts have been developed over the last two hundred years, making a wide range of beers possible from pale ale to dark stout.

SEMs of carbonised grain from Balbridie 'timber hall', Fife, Scotland
I spent a few years making funding applications, hoping to continue my research into the archaeological evidence for malt. That never happened but, working with the Satake Centre for Grain Process Engineering at UMIST, Manchester, I was able to get some scanning electron images of ancient carbonised grain from a neolithic site in Scotland.

The SEM images below were taken to accompany our funding applications and they were not originally intended for publication, but I think enough time has passed for me to now put them up on my blog and share them. The SEM work was done by a brewing research student. I am sorry to say I don't know her name and I did not get to meet her.

I was given six tiny carbonised grains from the thousands that had littered the floor of a 6000 year old, early neolithic rectangular timber building in Scotland. The building was destroyed by fire. Professor Ian Ralston, one of the original excavators, was kind enough to send me them. Three of the grains had missing embryos, visible with the naked aye and very clear under a normal microscope. One of the grains was examined using a scanning electron microscope and it shows the missing embryo, on the right, indicating that it has begun to germinate.

More of the grains from the site would need to be examined, to identify how many had begun to germinate. If it turns out to be a high percentage, and if the grains are friable and poorly preserved, then this is a deliberate malting for the production of ale in neolithic Scotland. Several SEM images of the same grain were made. The image below shows that the endosperm of the grain has been badly damaged by the fire. But it is possible to just about see the aleurone layer, beneath the husk.

Moving in closer to see the detail of the husk, we were very surprised indeed to see that the aleurone layer, that special layer of cells that kick starts the germination process, is visible, intact and well preserved. The husk has begun to be broken down by other enzymes, as can be seen in the bottom left of the image, and the grain was friable and fragile. All these are good indications of being malted.

This final image of that little carbonised grain show how well the individual cells of the aleurone layer have been preserved. They look rather like sponges, and some appear to have been activated. The more you look at this image, the more detail you can see. It is possible to make out erosion pits, beneath the individual aleurone layer cells, that indicate that the enzymes have begun to hydrolyse starch into sugars.

This is my favourite SEM image of an ancient grain. I think it would be a very good research project for someone to look at ancient carbonised grain from as many sites as possible. Changes in the aleurone layer cells and degradation of the husk might prove to be important criteria for the identification of malt. 

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desperately seeking sugars

A few years ago, we were standing beside the trench of an excavation on Orkney. Lots of serious digging was going on. One of the diggers looked up, recognised us and said something like...

oh hello! Are you those brewing people?

Yes, that's us. 

Can you tell me how to make Heather Ale?

Of course, we replied. No problem.

Because we've got loads of heather growing around our house and we want to make some beer with it! 

But you can't make beer from flowers, we replied. Flowers provide the flavouring, the preservative ... you have to add sugar. That's what ferments into alcohol. 

beer made from flowers?
We began to think that, maybe, when some archaeologists had come across our work on prehistoric brewing and heard about our ancient style meadowsweet ale, they thought that we had made it from meadowsweet flowers. We had not considered that before. Later that month, our suspicions were confirmed when we did a prehistoric brewing demonstration at a neolithic feast, organised by the Orkney Archaeology Society. I think it was in 2008. Over an open fire, with just the hot ashes, we heated some water in an earthenware bowl. It was our mini mash tun.

When the water was clear enough for us to see our reflection, we knew it was the right temperature.We added the crushed malt. This is known as 'the strike'. The local hens came running when we got the malt sack out of the van. Soon, there was the sweet aroma of the saccharification, this is when the enzymes re-activate in the mash tun and turn grain starch into malt sugar. It smells delicious. Folk began to wander over to find out what was going on. Some of them tasted the mash.

We were asked how much sugar we had added. None, said Graham. All the sugars come from the malted barley in the mash tun. No, go on, there must be some added sugar in there! No, we assured them, there was no added sugar. Later a couple of ladies asked how many flowers we had used to make our ancient brew. The answer was about an ounce and a half for five gallons of ale. They walked away, shaking their heads in disbelief. I am quite sure that they had confused what we were doing with making a flower wine.

Check out the recipes for "country wines" online - they all have a couple of pounds of sugar per gallon in the list of ingredients.

Quite simply, it is not possible to make ale or beer from flowers.

beer made from birch sap? 
Birch sap contains very few sugars, less than one per cent. It is more like a sweet water. You could collect a lot of it, then boil it to make a syrup but it is hardly a practical way of obtaining sugars for fermentation. John Wright, writing in the Guardian, explains how to make birch sap wine. The ingredients include 1.8 kilos of sugar and grape juice concentrate.

beer made from bread?
Some archaeological and anthropological sources suggest that beer and ale were made from bread in ancient times. There is a common myth that beer was discovered when a loaf of bread fell into a bucket of water and fermented overnight.

If it was really possible to make beer from bread in ancient times, then why aren't we doing it now? Surely people would be queuing up to buy loaves of bread so that they could throw them into a bucket of water to ferment for a few days. Home brewed Egyptian beer. It might taste horrible. It might be a bit weak and sour. But that's what it was like in the past. Wasn't it?

Sorry to disappoint you, but it is not possible to make beer from bread. The biochemistry does not allow it. There are no sugars in bread to ferment into alcohol. However, a quick search on the internet shows how the idea that bread can be somehow transformed into beer still prevails. There are lots of different methods suggested. Here is just one example:

" Barley was used to make beer. The barley was combined with yeast and made into a dough which was part-baked in a stone oven. It was then crumbled into a large vat, mixed with water and allowed to ferment before being flavoured with dates or honey. Recent evidence suggests that barley malt may also have been used in the process."  www.historyonthenet.com

If you crush the barley into flour, then make a bread you have destroyed the fabric of the grain. There is no possibility of germination, no possibility of starches being turned into sugars. No beer or ale. Baking in a hot oven alone would be enough to destroy any enzymes. It would also destroy the yeast. This method would not work.

The recent evidence, referred to above, is that of Delwen Samuel. Analysis of residues on 3000 year old ancient Egyptian pottery showed erosion pits from the enzymatic action in the the individual starch granules. This proved that the grain had begun germination - it was malt.

Delwen Samuel's papers are available online. In 1997 she published 'Fermentation Technology 3000 years ago. The Archaeology of Ancient Egyptian beer'. The scanning electron microscope images of pitted starch granules can be seen there.

beer is made from malt
To make ale or beer, you need malt. This is grain - barley, wheat, oats or rye - that has begun to germinate. Germination stimulates the production of the starch converting enzymes. Making malt is a specialised craft in itself. There is far more to it than soaking grain in a bucket, then letting it sprout. The two crafts of maltster and brewer are separate today. The maltster supplies the brewer with malted grain.

mashing 

The brewer heats the crushed malt with hot water in the mash tun to make malt sugars. Sugars ferment into alcohol. It's a simple but very obvious thing. Over the years, we have given demonstrations of what happens in the mash tun, of how the crushed malted grain is heated up gently, to make malt sugars. This is known as the mash, or saccharification - the enzymes in the malt are active at about 65 to 67 degrees Centigrade, so this is the temperature to aim at in your mash tun. 

The mash tun can be an earthenware bowl, heated in the ashes of a fire. We have done this many times, the image below is from a demonstration at Eindhoven Museum. I went there in 2009, as part of a brewing forum organised by EXARC.

a mashing demonstration at Eindhoven,

Or the mash tun can be a wooden trough in the ground, heated by hot rocks. We have done this several times. The pioneers of the technique are the Moore Group archaeologists. The video of their hot rock mash in a wooden trough, first done in 2007, is now legendary.

Given that thermometers are a recent invention, brewers in the past learned how to judge this temperature by skill and experience. John Tyndall, giving a lecture on Fermentation at the Glasgow Science Lectures Association, October 19th, 1876 said

"Our prehistoric fathers may have been savages, but they were clever and observant ones ... the art and practice of the brewer are founded on empirical observation ... the brewer learnt from long experience the conditions not the reasons for success" 

In the scholarly literature and in many of the archaeological and anthropological academic papers about making beer in ancient times, a wide range of beer making ingredients have been suggested - barley, wheat, dates, figs, fruit, berries, birch sap or birch syrup, honey or flowers and leaves.

All that any brewer needs to make ale or beer is water, malt, herbs and/or hops and yeast.

Wort is the sweet liquid that comes from the mash tun after sparging. The exotic ingredients of the scholarly papers can enhance the ale in several ways, by preserving, flavouring or by providing medicinal or other properties. But they do not provide the primary fermentable sugars. This comes from the grain, which has been malted, mashed, lautered and sparged. Barley is a reliable source of sugars for fermentation. You just need to know how to make it.

There is no need to go desperately seeking sugars.

Just understand the malt, the mash and the saccharification that occurs in the mash tun.

further reading
The Big Book of Brewing by David Line
In our opinion, this is the best book to read on the processes of malting, mashing, lautering, sparging and fermentation.

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two years later 

I went to a talk recently, it was about the neolithic, grooved ware and the use of pottery. My impression, after talking to several archaeologists, is that it still seems to be a widely held belief among archaeologists that 'alcohol production' in prehistory was no more than guesswork. It involved mixing up random stuff to make 'something alcoholic that did not taste very nice'. No skill involved.

Beakers were for Beer! part two: a birch bark bucket with residues

The image below might not, at first, seem to have anything to do with prehistoric ale. Or beer even. This is the oak log coffin of the young Bronze Age woman known as the Egtved Girl. She died about 3300 years ago. Her oak coffin was found by a farmer, Peter Platz, within a large grassy burial mound in southern Jutland, Denmark. He called in the archaeologists from the local museum who excavated it in 1921. Recent dendrochronological dating of the oak log coffin reveals that the tree was felled in 1370 BC. The North European Bronze Age is a fascinating place to go and visit online to understand some of the background to the Egtved Girl's world. There is a lot of information out there - for example, this atmospheric short film. And lots of pictures of the things that they made and wore and used - the bronze figurines, the sun chariot, the drinking vessels, the well preserved clothing and even a wooden folding seat.

 

What the archaeologists discovered within the Egtved Girl's oak coffin was quite astonishing ... there was no skeleton, just a few fingernails and some of her teeth, brains and hair remained. Her bones had been destroyed by the acidic conditions. But the clothes and the grave goods of the young woman had survived the millennia virtually intact. She had been buried wearing a woven woolen tunic top, a corded wool skirt and a woven belt with a bronze spiked disc. Bronze bracelets adorned her arms. Most people agree that she was a dancer, maybe even a priestess, and that she was buried in her dancing clothes. A small bronze figurine, doing a back flip and wearing a skirt like that of the Egtved Girl, was found at Grevensvaenge, Zealand, Denmark. It was part of a small Bronze Age hoard that was first reported in 1779. Over the years, several of the figurines have been lost but the little bronze acrobatic dancer is now in the National Museum of Denmark.

a reconstruction of the Egtved Girl's clothes: details here

Now the oak coffin, the clothes and grave goods have been reconstructed and there is a wonderful display in the National Museum of Denmark. She is visited by thousands of people. There is so much on the internet about the Egtved Girl that it is easy to find out about her. She even has a few Facebook friends ...

I first came across reports of the Egtved Girl through reading the bibliography of Eva Koch's article Prehistoric Plant Food of Denmark, published in 1999. Archaeology can be a bit like a detective story. In the days before the internet was everywhere, the bibliography at the end of an academic paper was probably the only lead you had to find the next piece of information. What interested me about this young woman's grave was the discovery and subsequent analysis of cereal based organic residues in a birch bark bucket that had been placed in the log coffin.

residues in a birch bark bucket
The reconstruction at the National Museum shows how she was laid upon a cow skin. A bundle of cloth, at her feet, contains the burnt bones of a small child, aged 5 or 6 years old. Also at her feet was a bucket made of birch bark. Someone noticed that there was a thick, dark brown residue at the bottom of the bucket. It was analysed in 1929 by Bille Gram. For all you fellow bibliography hunters, this is the reference for the original archaeobotanical report ... over the years I have tried, and failed, to get hold of a copy. In either Danish or English. Maybe you can find it. If you do, please let me know!  

Th. Thomsen (1929): Egekistefundet fra Egtved. Nordiske Fortidsminder Andet Bind. København. (In this book, her drink is mentioned by Bille Gram on page 184 note 2, apparently)

the birch bark bucket 

I don't know how the analysis of the residue was undertaken. I would imagine that it involved a microscope and not a lot else, given that it was done in 1929. The bucket had contained an alcoholic drink - it was probably ale - made from wheat, cowberries or possibly cranberries, bog myrtle, some other plants and perhaps with added honey.

Descriptions of the residue analysis vary in the archaeological literature, which is why I would like to read the original archaeobotanical report. Some archaeologists mention the presence of clover pollen, others mention lime flower pollen. Mixed pollens often indicate the addition of honey. It has been suggested in some academic papers that the "beer" was made from the berries, but any all grain brewer knows that this is simply not possible. The primary source of fermentable sugars had to come from the grain - or rather, from grain that had been malted. It could have been either malted wheat or malted barley or a mixture of both.

Residue analysis provides you with a list of probable ingredients. It does not provide you with a recipe. Nor will it tell you the ratio of ingredients to each other, nor the quantities that are required. To make a similar brew from the list of ingredients you need a recipe. In other words, you need to know and understand the brewing process, the techniques and the methodology of how to make malt and ale.

making malt and ale
There seems to be some confusion amongst archaeologists and anthropologists about what malt is, how it is made and how the brewer uses it. Malt is sometimes described as 'toasted barley sprouts' or even as 'sprouted barley' - something like beansprouts. Neither of these is an accurate description. Malt is grain that has been steeped and aerated in water, then spread out on a smooth, level floor within a dark but well ventilated building to begin to germinate. When the acrospire (the root and shoot) is no more than one third the length of the grain, it is dried gently in a kiln. This is traditional floor malting and this process makes pale malt. Specialist malts are made by roasting at higher temperatures.

I have read descriptions of brewing in academic papers, explaining that malt is 'boiled with water' to make a 'malt solution'  but this would not work at all. The brewer mixes crushed pale malt with hot (not boiling) water to make a sweet wort. This process is called the 'mash' or 'saccharification'. If you boil the malt, then the enzymes that convert starch into sugars are destroyed and you will never make anything fermentable. Specialist dark malts, such as crystal or chocolate malt, are used for colour and flavour and do not provide any sugars in the mash tun.

I began to discuss these issues in an an earlier post and I will certainly go back to these fundamental aspects of making malt and ale in future posts. My last academic paper The Craft of the Maltster is about to be published as I write this blog post. I was given permission to put it online. The book of the conference will be out soon. Floor malting techniques have not changed over millennia.


the ingredients, according to residue analysis of the Egtved bucket

• wheat - this was probably identified, under the microscope, by the presence of a part of a grain husk. Could it have been a bit of barley husk? This is possible. During the brewing process, specifically in the mash tun, the malted grain is mixed with hot water and the grains become broken up. As mentioned above, whether it was wheat, barley or a mixture of both, the grain had to have been malted. Malt provides the primary fermentable sugars for ale and beer.

• cowberries - not the main source of fermentable sugars. These are very tart, sharp tasting berries. Probably used as an adjunct. Cowberries, also known as lingonberries were probably identified in the Egtved bucket residue analysis by the presence of seeds. It can be tricky to identify the specific berry type from the seed alone. 

• bog myrtle - also known as myrica gale, this leafy shrub has been used for millennia as a 'brewer's herb'. It both preserves and flavours the ale and it was used before the introduction of hops in medieval times. Many other plants and herbs can be used in brewing ale. We have used meadowsweet and juniper berries in our ancient ales. Yarrow is another commonly used plant as an alternative to hops. These are known as gruit and these days you can buy a wide variety of these ancient and traditional ales in the shops, made by several different brewing companies. 

• lime pollen, clover pollen - the presence of these in the bucket residue might indicate the addition of some honey to the ale. Again, it is an adjunct and not a primary source of sugars for fermentation. Alternatively, the pollen might indicate the addition of lime flowers and clover to the wort, for flavour and/or preservation.  

how we would make an 'Egtved Ale'- the basic techniques and recipe
We have been making ancient style ales for fifteen years now. Small batches, a few gallons at a time, in our home brewery. To recreate the ale that was in the Egtved bucket we would, first of all, get some malted grain. If possible, we would try to obtain some malted bere - an ancient strain of barley. The grain is skinny, much thinner than modern barley. We have used bere malt successfully to make an ale flavoured and preserved with a few dried meadowsweet flowers instead of hops.

our mash tun 

We would mash the crushed malt with hot water in the mash tun for about one hour. Grist is the brewer's term for crushed malt. Brewers refer to the water used for brewing as 'liquor'. It is not alcoholic. Then we would lauter, that is, collect the first runnings of sweet wort from the mash tun,  and then sparge. This involves running several gallons of hot water through the mash and collecting more wort. As far as quantities and ratios are concerned, we would use about 15 pounds of malted grain to make roughly 8 or 9 gallons of wort.

Cowberries could be added to the mash tun, or they could be added to the wort during the boil. It is difficult to know exactly how many to add, but when we made our Juniper Ale with berries, we used just a few ounces to twelve pounds of crushed malt. Having obtained the wort we would boil it, together with some sprigs of bog myrtle and/or lime flowers and clover flowers. Yeast would be added, most likely in the form of barm from a previous brew. Leave the ale to ferment for a few days, then rack it off into a fresh container and see what it tastes like.

strange brews
Over the last few years, there have been some rather strange re-creations of the alcoholic drink hinted at by the residues in the birch bark bucket found at Egtved. Not all of them are convincing. I watched a TV programme recently that showed the archaeologist Neil Oliver drinking an 'ancient style brew'. I think, but am not entirely sure, that it was supposed to be based upon the Egtved residues but, sadly, some of the basic ingredients had been altered. Apple juice was used instead of wort. The herbs, honey and berries were included. I don't think that apple juice would have been an option for those Bronze Age brewers 3300 years ago. Crabapples were the only available 'apple' and these are very sour. Even today, when people make a crabapple wine, they have to add a large quantity of sugar because the crabapples are not sweet enough to ferment by themselves. Crabapples also require a modern press to extract the juice. I cannot work out how the juice could have been pressed from crabapples in Bronze Age Denmark.

Another strange brew is Kvasir, made recently by the Dogfish Head Brewery in collaboration with Professor Pat McGovern, who is sometimes referred to as the Beer Archaeologist. For some reason, concentrated birch syrup was included in the Egtved inspired brew. I have no idea why, since this ingredient was not identified in the analysis of the residue from the birch bark bucket. Concentrated birch syrup is made using modern processing techniques. I think the word to remember here is 'inspired'. I don't think they were aiming to actually recreate an accurate copy of the 3300 year old ale, rather, they are making a modern Craft Beer, USA style, that pays homage to the Egtved Girl. I have found no mention of malt, mash tun or wort in the media coverage of this brew.

It is odd that she is referred to as a 'leather clad priestess' when she was actually wearing a tunic made from woven wool and a corded skirt. This is a very well known detail of the Egtved Girl's clothing. When she was first discovered, in 1921, some  archaeologists thought that there must have been a linen undergarment because the 'string skirt' was so revealing.

There are plans to make a commercial beer to a similar recipe in Sweden - Arketyp. This brew appears to have crushed pale malt as an ingredient, but it also includes concentrated birch syrup. Again, I don't understand the reason for this addition to the ale unless it is to make a kind of 'Nordic Grog'. Professor McGovern has proposed, in a recent academic paper, that this is what people made and drank throughout Europe in prehistory - some kind of mixed alcoholic drink made up of different components, such as birch syrup, wine and herbs. Although the biochemical analysis of four residues is incredibly detailed, there is nothing in the paper about malting, mashing, malt sugars or the brewing process.

For some of these strange and exotic brews, it seems as if the archaeologists who try to recreate them are struggling to find fermentable sugars, while neglecting the malt and the wort. Barley, and wheat, are an excellent source of sugars for fermentation  if processed in the right way. Maybe you have to be a brewer to understand these processes.

Egtvedpigens Bryg - made with malt, water, herbs and honey
I am very pleased to say that the National Museum of Denmark, working together with the Skands Brewery, have made an authentic ale based upon the ingredients identified in the bucket residue analysis. It should be available in the Museum Shop. If you are lucky enough to go and visit the Egtved Girl in Denmark, maybe you could try some. The details of this ale are, as yet, sparse on the internet. The launch party was on the 22nd of March 2014, so this really is the most recent and, for me, the most exciting development in the long story of the Egtved Girl and her bucket of ale.

I have found some Press Releases online, in Danish and translated into English. I expect that we will be hearing a lot more about it in the future.

launched recently, a modern commercial version of the Egtved Ale

Beakers were for Beer! part one: ale, mead & residues

Beakers were for beer. I was told this back in 1995, in my final year as an archaeology undergraduate. There was absolutely no doubt about this, or so it seemed at the time. I made a note to look further into the idea. This was when my interest in ancient brewing techniques began. I had never thought about it before, but, being married to a home brewer of fine ales, made from all grain, I was intrigued. He would carry a 25 kilogram sack of crushed malt from the Brewing Supplies shop into the house, and then after about a week, he would have made us some excellent beer. A 25 kilo sack of malt would make 4 brews of 8 or 9 gallons each. Yes, I'm mixing Imperial and Metric but I am not bothered about that. The point is that you can make plenty of beer from 25 kilos of malt.

How did those Bronze Age folk, living in Britain around 4000 years ago, make their beer? I asked several people in the Archaeology Department but nobody seemed to know. They all thought I was crazy, looking for the archaeological evidence of beer brewing. You won't find anything, they said.

A paper was cited by the lecturer: Burgess and Shennan: The Beaker Phenomenon: some suggestions. It had been presented at a conference "Settlement and economy in the third and second millennia BC" and the proceedings were published in 1976 as a British Archaeological Report (BAR 33). It is cited in dozens, if not hundreds of academic bibliographies about the Bronze Age of the British Isles. It has become a classic paper, but it is not easy to find unless you have access to a University Library. That is to say that I have not managed to find access to a copy online.

One of the arguments of the paper was that Beakers were made specially for the drinking of beer. They proposed that a warrior cult existed in Bronze Age Britain, with some people buried with grave goods that reflected their prestige, high status and lifestyle. Grave goods often included a drinking vessel - a finely made and decorated pottery 'beaker' from which they drank their beer. No archaeological evidence, such as residue analysis, was presented in the paper.

The Amesbury Archer, referred to by the media as the 'King' of Stonehenge was considered to have been an important person and someone of high status, since he was buried with lots of grave goods, including five fine beakers, gold jewellery, the equipment for making metal and a slate wrist guard that hints at his prowess with a bow and arrows.

beaker from Hemp Knoll, Avebury

If beakers were for beer, then what is the archaeological evidence? Did it taste like the beer that we drink today? Who made it? Were the brewers men or women? What's the story?

Strictly speaking, when referring to prehistoric brewing from cereals, it should be called ale, not beer. What's the difference? Ale and beer are both made from malted grain - barley, wheat, oats or rye. Ale is preserved and flavoured with a variety of herbs, such as bog myrtle, heather, yarrow, juniper or meadowsweet. Beer is flavoured with hops which were introduced to the brewing process only recently, in medieval times. Spices can also be used. Today, we tend to use the terms 'ale' and 'beer' fairly indiscriminately.

For anyone interested in ancient ale, the discovery of cereal based residues on old pots has to be one of the most exciting things. Research was very different in those days. In the late 1990s the internet was in its' infancy. Internet search engines were a rare and wonderful thing, to be accessed by a few lucky academics. Charles Mount has written about how University research has changed over the last 20 years here. He is writing about University College Dublin, but the story is the same throughout UK Universities.

So, for me, my first research involved going to the John Rylands Library, looking through the card index systems, finding archaeology journals and reading lots of excavation reports. I spent many hours doing this. I started with the Proceedings of the Society of Antiquaries of Scotland, fondly known as the PSAS (now available online). It is an excellent resource. I soon stumbled on excavation reports that had some intriguing descriptions of cereal based residues on pottery, together with a detailed pollen analysis. Just what I was looking for.

cereal based residues on pottery
A couple of years after the Burgess and Shennan paper was published, a discovery was made in Fife, Scotland, that supported their thesis that beakers were for beer drinking in the Bronze Age. 

In 1978, excavations by a team led by Gordon Barclay at the site of a timber circle, bank and ditch (c2330 ± 60BC) at North Mains, Strathallan, Scotland, revealed several cist burials  In one of these, a female cist burial, there was a fine, complete Food Vessel with a deposit of organic material still adhering to the inner surface of the pot, after thousands of years. It was described as a 'black greasy material on the internal surfaces'. Such discoveries are extremely  rare.

The cist was situated in the centre of the timber circle. Fortunately, it had remained partially sealed, hence the unusual survival of the organic material. Analysis of the residues revealed high percentages of cereal pollen and meadowsweet pollen. It was interpreted as being the probable remains of a cereal based fermented drink. The radiocarbon date was 1540 ± 65BC. The analysis (below) is on pages 178 to 180 of the excavation report in PSAS Volume 113. The details are important and of interest to any all grain brewer. The 'human interference' that has introduced charcoal to and that is referred to might be the drying of malted grain, rather than parching harvested grain.

There is a Table on page 179 which gives the details and percentages of the pollen finds. Of course, I recommend reading the whole report, which can be downloaded from the PSAS website. That is because I really like to read the original excavation reports rather than secondhand interpretations. It is almost like being there! The descriptions of the pottery finds (between pages 155 and 163) are also informative.

When I showed this pollen analysis to my husband he said 'I can make that. I just need to replace the hops with some meadowsweet flowers.' And so our research into recreating ancient ales began.

POLLEN ANALYSIS OF DEPOSITS IN A FOOD VESSEL FROM THE HENGE MONUMENT, NORTH MAINS                         S Bohncke
INTRODUCTION
Burial B was accompanied by a food vessel (SF17), discovered lying on its side by the skull. Within the pot a small deposit of black greasy material was found. As the analysis of material within vessels has proved valuable (Dickson 1978) samples of this deposit and scrapings from the pot wall were subjected to pollen analysis. 

MATERIAL AND METHODS
Part of the black greasy material was used for the preparation of two pollen samples and another sample was scraped from the inner fabric of the pot. All samples were treated with hydrogen fluoride to remove the silaceous component and were subsequently subjected to Erdtman's acetolysis. Microscope slides were then prepared using glycerol jel as an embedding medium.
 
RESULT AND DISCUSSION 
High percentages of Filipendula (meadowsweet) pollen (74-1 %, 77-8%, 84% (scraping)) and relatively high percentages of cerealia pollen were noted. There was also a large proportion of charcoal fragments. Within the Filipendula grains there was a wide range of variation in the states of preservation. The well preserved type is the tricolpate micro echinate pollen in which the pores are clearly pouting. The very corroded type lacks the characteristic pores but the wall structure is not affected. Immature pollen was also present. Relatively high proportions of Filipendula can be attributed in part to selective corrosion as Filipendula has a relatively thick wall but this could not explain the 74-1-84% found in these samples.

Cereals are self pollinating, the result being that little pollen is dispersed into the air. The anthers remain within the spikelets so that on the fully grown cereal pollen grains could still be present, though most would be lost during the winnowing process. Compared with the other species the cereals are over represented in both samples. This is probably the result of human interference. The charcoal in the samples might have originated in the processing of the grain (eg roasting to remove chaff), however the cereal pollen were not burnt and this therefore seems unlikely. The charcoal may also have found its way into the pot during the burial ritual or have been in the pot already, perhaps as the result of firing a new vessel for the burial. The remaining pollen almost certainly came accidentally into the food vessel and represented a part of the contemporary pollen rain. The presence of pollen of plants flowering at different times of the year (eg Corylus March-April, Polypodium August-September) might be explained by the addition of pollen-bearing water to whatever was contained in the vessel or its incorporation in the manufacture of the contents.

Dickson (1978) in his analysis of the Ashgrove beaker scrapings discovered very high proportions of Tilia and Filipendula and concluded that the vessel had contained lime honey or mead flavoured with meadowsweet. The North Mains food vessel contained neither lime pollen nor sufficient pollen from other honey-producing plants. The 2-4-3-7% of Compositae pollen were not sufficient for a honey based on Compositae alone. The high proportion of cereal pollen grains might suggest either a porridge of cereals (eg frumenty) or a fermented ale, flavoured with meadowsweet flowers or extract. The name 'meadow-sweet' originates from mead-sweet as it was used to flavour mead and other drinks. It is distinctly possible therefore that the North Mains food vessel contained a fermented drink.

the Ashgrove beaker
Mention is made of the Ashgrove Beaker. This was found in an excavation of a Bronze Age cist burial by Audrey Henshall and was published in Antiquity in 1963. As well as the skeleton and a beaker, there was also a fine dagger. It seemed that the pot had fallen over, spilling its' contents on the floor of the cist. James Dickson analysed the residues in the 1970s and he also published his results in Antiquity.

Pollen analysis revealed large amounts of immature lime pollen and meadowsweet pollen, which was interpreted as the remains of mead but sadly, it was not radiocarbon-dated. Nor did they look for cereal residues. Ian Hornsey discusses the implications of this discovery in his book, The History of Beer.

my first article

These discoveries, and others, led me to write my first article about the archaeology of ancient ale, towards the end of 1996. Descriptions of residues on Grooved Ware pottery from the neolithic site of Balfarg are very similar to those found on Beaker pottery. It was beginning to look as if making ale from the grain was a Neolithic, not a Bronze Age phenomenon.

I was very pleased and proud to be the cover girl for BA19 and I have Simon Denison, the then editor of British Archaeology, to thank for that. He was interested in my work and very supportive.

The picture shows the Strathallan or North Mains food vessel, with meadowsweet flowers surrounding it. These flowers would have been the flavouring and preservative for the ale, the base of which would have been a wort made from crushed malted cereal - barley and/or wheat.

Finding Magic in Stone Age Ale - my first article - you can read it here.

That's all for this blog - more than enough for you to be getting on with. I find it odd that in 2014, particularly in the UK, there seems to be a taboo surrounding any discussion by archaeologists of malt and ale in prehistory.

The evidence is there, if you know and understand what the brewing process is and what you have to look for in the archaeological record.

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... my next blog will be about the Egtved Girl's Brew, the residues of which were found in a birch bark bucket in her oak log coffin in Denmark ... there are some details here.

Please get in touch with me if you have made a beer based upon these residues, if you know of someone who has or if you have been lucky enough to taste one of these brews.

I know about the 'Nordic Grog' made by Dogfish Head Brewery, under the guidance of Professor Pat McGovern. It was recently marketed as Kvasir, named after a Nordic Princess. 

I want to hear about any real home brewers who have had a go at recreating it.

Thankyou! 

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further reading
Burgess, C. & Shennan, S. 1976. The Beaker Phenomenon: some suggestions. In Burgess, C Miket, R. (eds.)  Settlement and economy in the third and second millennia BC : papers delivered at a conference organised by the Department of Adult Education, University of Newcastle upon Tyne, B.A.R 33, Oxford, 309-331.

Barclay, G. (1984a) 'Sites of the third millenium BC to the first millenium AD at North Mains, Strathallan, Perthshire', Proceedings of the Society of Antiquaries of Scotland. Vol.113


Dickson, J. 1978 'Bronze age mead', Antiquity, 52 (1978), 108-13.