Tuesday 30 November 2021

Beakers were for beer part 4

This is Graham Dineley writing this blog. All ideas, opinions and mistakes are entirely my own and my responsibility. I welcome comments and discussion, please feel free to do so.  

It's a long time since 'beakers were for beer' parts 1, 2 and 3 were written by Merryn. Something happened recently that caught our attention and so the brewer decided to write part 4. It involves a television series, the Achavanich Beaker and there's some Grooved Ware thrown in at the end for good measure.

BBC's "A History of Ancient Britain" with Neil Oliver

Early last year, April I think, we were making silk face masks during lock-down to give to family and friends, as PPE was virtually unobtainable. We were idly watching TV when these Neil Oliver episodes were repeated on PBS America. We had contributed some meadowsweet ale to this series, at the request of the production team and we looked forward to seeing it again. In the final episode about the Bronze Age Neil is seen walking around Dartmoor discussing villages. Then the camera cuts to Neil sitting in a pub discussing developments of this civilisation. We were shocked and surprised to see that the next sequence of him drinking beer from a beaker had been removed. However Merryn still appears in the credits.

I was so surprised at this, that for confirmation I bought the boxed set of DVDs to confirm that editing. On the second DVD at 1:51:35 he enters the pub, and then at 1:52:57 it cuts to him walking around Dartmoor again and the bit where he drinks from a beaker has been excised.

Back in March 2010, a member of the production team for this series approached us with a view to us providing them with some of our prehistoric beer. They wrote:

"While we figure out exactly when we might want to feature your beer in the series, I thought it might be a good idea to commission some from you, so that it's on hand when we need it! Would that be OK?"

We were delighted, at last someone was taking us seriously and we might get an opportunity to put the idea to a wider audience. So I replied:

"Graham here, the brewer. Yes I will make some meadowsweet ale for your programme. It will take about 4-6 weeks, longer if you want it to be very clear. At the moment I am waiting for more malt from my suppliers, and I will let you know when I start it. The name "meadowsweet" comes from the Saxon "medhu" for mead. The Saxons and the Vikings did not readily distinguish between ale and mead, and in fact meadowsweet ale tastes very much like mead. This kind of drink came to Britain with the first farmers in the Neolithic, as part of their package, and it was definitely drunk in the Bronze Age, Iron Age, Saxon era and Viking times, right through to the introduction of hops by the church in mediaeval times.

The reply came back:

"Dear Graham,
Many thanks indeed for this email. Please could you send us the 2 litres of ale to arrive by next week? The address to send it to is:
Room MC5A4 BBC Media Centre
201 Wood Lane.
W12 7TQ

Please also let us know how we can pay you for the ale and the shipping costs. Thanks again and best wishes."

I replied:

"Hi, the ale and wort are in the post, and they should arrive tomorrow or Saturday. The postage was £8.22, so you could send a cheque.
The meadowsweet ale is free, as I can only give it away; customs and excise regulations prohibit the sale of home brew :-). However you could repay us for the ale by giving some exposure to our idea that "The first farmers in Britain brought not only cattle, cereals and ceramics, but also the skills to brew ale for their rituals and ceremonies. It came as a complete package." Also if you could please report to us any feedback or opinions on this idea that the other contributors to this production may offer.
We believe that this meadowsweet ale is not very different to that brewed in the Neolithic through the Bronze Age, Iron Age, Roman Era (strong ale, slaves and hunting dogs were major exports from Britain according to Julius Caesar) and Viking times until the Mediaeval times when hops were introduced from Europe. Of course the Georgian industrial breweries were a major change.
The meadowsweet ale contains salycilates from the meadowsweet flowers and so should not be consumed by anyone allergic to aspirin.
P.S. There still some 15 litres of ale left, so if you would like any more of this batch you should let me know soon!"

This reply came back:

"Hi Graham

Sorry about this, but could you send us another 2 litres so that we have 4 in total? We will of course pay you for this but have to do it by bank transfer so please send me your bank account details.

Please confirm this is all OK."

Thanks again.

I replied:

"Hi, yes I can send you another 2 litres, but the first opportunity now will be Tuesdays post, which should arrive Wednesday/Thursday.
I guess someone will have tasted it by now, any comments or feedback?
One thing I forgot to mention, ingredients. 15lbs crushed malt, 5 gallons of water, ½ oz dried meadowsweet flowers and 2 teaspoons of yeast. NO SUGAR, NO HONEY.
All the alcohol comes from the malt sugars from the barley malt, that is the wort.
That is also where most of the flavour comes from too!
I will send you the bank details when I know how much the second posting costs.

We heard absolutely nothing more from the BBC team after that, except that I had to sign and return a form which stated that, "This beer is fit for human consumption." I did this and also added, with an impish sense of humour, "Sole intended purpose." So we waited for the series to be aired on TV.

Neil Oliver's series 'A History of Ancient Britain' finally aired on TV in 2011. We eagerly waited to see what they showed. In the fourth episode about the Bronze Age Neil Oliver is discussing villages, whilst walking around Dartmoor. The camera cuts to him entering a pub, and sitting with a pint of beer, discussing developments of that culture. Then it cuts to him sitting on a rock, drinking beer from a Bell Beaker. I could tell instantly that it wasn't my beer, because it was frothy and had bubbles in it. My beer was flat. So it must have come from a bottle or a can of beer. They did not use our beer. I often wonder if anybody even tasted it, or whether it was thrown away and poured down the sink.

There was no mention of us, or our work, but at least we were happy that the idea that 'beakers were for beer' was being promoted.

It could only be some powerful and influential archaeologists who could persuade the BBC to edit the beaker beer from that episode. We are quite accustomed to being ignored, and even bullied by some, but this a gross abuse of power and influence, for personal or political reasons, and it verges on totalitarian thought police.

The Achavanich Beaker

The Achavanich Beaker was found in Caithness, Scotland, in February 1987. Below is archaeologist Robert Gourlay's description of the site and also a pamphlet guide, with a map and illustrations. The words are the same in both documents.

Gourlay's report, page 1.

Gourlay's report, page 2.

The Achavanich Beaker

Brochure, outer page. Folded in three.

Brochure, inner page. Folded in three.

This five page document was available online on the Highland Regional Council's web site as a PDF. I downloaded it on 15th May 2015, as at that time it was the best evidence for early beer brewing in Scotland. The pages were in a different order then, first the illustration of the Beaker, then the archaeologist's report, and then the illustrated brochure, inner first, and outer last. 

Now, with the re-evaluation of the site by the Achavanich Beaker Burial Project, that document has disappeared. Only Dr Gourlay's report is available as a PDF. I have copies of the original five page PDF, if anybody wants it. Contact us please.

The report on the residues from the beaker make very interesting reading for any beer or brewing historian. The original report says:

"The contents of the beaker - no more than a slight smear on the inside - were analysed by palaeobotanist Dr Brian Moffatt in Edinburgh. His preliminary results suggest that the vessel originally held a mixture of the following:

(a) Prepared cereal - a course mixture of barley and oats with much chaff and stem. Judging from the still visible 'pour-mark' on the inside, it was a thin porridge or gruel.

(b) Honey - probably wild, it contains pollen from flowers which grew in a variety of habitats such as moorland, woodland, meadowland and pasture, scrubland, watersides, and even by the sea.

(c) Added flowers and fruits - presumably for extra flavouring. These include meadowsweet, bramble, and wood sage.

(d) The sap of birch and alder trees.

Dr Moffatt concludes: 'There are here multiple bases for fermentation, and the outcome of collecting them would be an "alcoholic hotchpotch".' This then, could have been the earliest known alcohol from Caithness' "

I don't know why, but there seems to be a concerted crusade against Beakers being used for ale or beer. This aspect of the contents of the beaker seems to be controversial, perhaps even unacceptable to some archaeologists.

The burial, the beaker and its' contents were recently re-evaluated by Maya Hoole and a team of archaeologists, including Dr Scott Timpany of the University of the Highlands and Islands who did the pollen analysis. The conclusion was that the beaker contents were purely medicinal. This was based upon the identification of Meadowsweet and St John's Wort pollen. See here for a summary of the Achavanich Beaker Burial Project's findings. Please note that there is no longer any mention of cereal residues or alcohol.

Both Meadowsweet and St John's Wort are gruit herbs, they were traditionally used to preserve ale and beer.

The fact that Brian Moffat's pollen analysis differs so much from Scott Timpany's could be explained by the pot being contaminated by background pollen since it's excavation. It has certainly been around quite a few places since it was first found. Moffatt had the benefit of working on the pot when it had been freshly excavated. Timpany's analysis conveniently excludes the cereal residues.

It is important to consider that some archaeologists are primarily sociologists and not scientists and sometimes make unwarranted assumptions. The active ingredients in Meadowsweet and St John's wort are alkaloids, and are only soluble in alcohol and not in water. The term alkaloid is derived from the word alcohol, itself an Arabic word in origin. By eliminating alcohol from the contents of the beaker their interpretation as purely medicinal has been rendered impossible. They have shot themselves in the foot!

Many traditional herbal remedies and medications are based upon the alkaloids in their herbs, and these preparations are all alcohol based. Many of the specialist ancient Egyptian brews were medicinal.


One of the largest and most important prehistoric ceremonial sites in eastern Scotland is known as Balfarg/Balbirnie and the Balfarg Riding School excavations. According to Canmore, the National Record of the Historic Environment of Scotland:

"These two sites (Balfarg and Balbirnie), along with structures that were found between them, form one of the most important groups of monuments of neolithic and bronze age date in eastern Scotland. The visible monuments are a henge and a small stone circle, now re-sited to the south-east of its original position; excavations between them have, however, revealed a ditched enclosure, two timber structures, cairns and burials as well as a large quantity of pottery."

See https://canmore.org.uk/site/29990/balfarg and https://canmore.org.uk/site/29959/balfarg-riding-school for all the details.

Plan of excavations at Balfarg, Balbirnie and Balfarg Riding School

Map: Barclay and Russell-White, G J and C J eds 'Excavations in the ceremonial complex of the fourth to second millennium at Balfarg/Balbirnie, Glenrothes, Fife', Proc Soc Antiq Scot, vol. 123, 1993, page 50

It was an extensive site, now a housing estate, and spanned from the Neolithic to the Bronze Age. There was a henge, two stone circles and two rectangular timber structures. Many Grooved Ware pottery sherds from large pots were found there and two of them, 63 and 64, had residues in them. 

This is what interests us, as brewing historians.

This a composite image, formed from pages 101 and 103. The scales have been preserved.

Merryn had been studying the archaeological literature on Bronze Age Beakers for residues indicative of beer brewing. When she read the descriptions of the residues on these two sherds of Grooved Ware, it was a light bulb moment for her. I can remember how excited she was at finding similar residues to those in Bronze Age pots to the ones from the Neolithic. 

This meant that the Neolithic people had probably been making malt and ale too. An idea that is still controversial, even 22 years after she submitted her M.Phil Thesis "Barley, Malt and Ale in the Neolithic", available in full on her Researchgate page. To make it easier to access, Merryn has put the Introduction, Summary and Discussion and Conclusions as blogs, entitled 'pieces from my thesis parts #1, #2, #3'. Follow these links if you are interested. There may be more to come.

Some archaeologists still reject this idea of beer, and they will not incorporate it into their interpretations. For example, the archaeologists currently excavating at the Ness of Brodgar refuse to discuss it with us. Maybe this is because they are theoretical sociologists, formerly known as post-processualists, and find the topic to be too scientific and technological to understand.

Brian Moffatt's analysis of the cereal based residues in 63 and 64 is that they contained;

"Processed cereal, both barley and oats, with meadowsweet, pollen and macroplant. Sample 14 had clumps, indicating a flower head of meadowsweet." 

There are other things that he identified in the residue, such as minute droplets of beeswax, fat hen pollen and even small amounts of solinaceae (hemlock family) pollen.

Encrustation on the outside of a sherd from pot 63.
Illustration from Gordon Barclay's booklet 'Balfarg:the prehistoric ceremonial complex' published by Historic Scotland, page 17

Interestingly, on the outside of a sherd of pot 63 Moffatt found an encrustation with black henbane pollen and broken henbane seeds in it. He says that black henbane can be used "to procure sleep and allay pains". This property of henbane has been known about for a long time, for example, from a Babylonian cuneiform tablet ~ 2250BC.

Brian Moffatt suggests that henbane can be applied topically or that it can be ingested. Ingesting henbane is very dangerous. It takes about 50% of the lethal dose to effect pain relief. The concentration of the toxins varies widely, both between plants and even within the same plant, as much as 6 fold or more. The only safe way to take henbane is by inhaling the smoke from the seeds, then it is easy to stop when the correct level has been achieved. Scribonius Largus, the physician to the Emperor Claudius, writes of the use of henbane in his Scriptorium Medicantorium, by placing henbane seeds on a hot plate of metal and inhaling the fumes. Mediaeval physicians also write about driving out the "tooth worm" with the fumes from burnt henbane seeds.

A broken pot sherd would be very good as a substrate for heating a henbane paste for the inhalation of the fumes. This could easily explain the presence of henbane seeds in the encrustation on the outside of the pot 63 sherd from Balfarg.

Interestingly henbane seeds were also found at Skara Brae, the Neolithic village on Orkney.

Henbane can also be a used as a hallucinogen. It seems that the thought that "hallucinogenic practises" had been performed at the ceremonial Neolithic site at Balfarg incensed some archaeologists. They quickly assembled a team to discredit Moffatt. This resulted in the rapid publication of an article in the Journal of Archaeological Science, by Long et al in 1999. I can't find a copy available other that the 'pay to view' paper here.

In their paper "Black Henbane (Hyoscyamus niger L.) in the Scottish Neolithic: a reevaluation of Palynological Findings from Grooved Ware Pottery at Balfarg Riding School and Henge" they made one fatally flawed assumption. See the underlined sections below:

"These residues occur as hard concretions that can be quite thick. They are assumed to be residues from the contents of the pottery vessels used in activities at the henge monument. One difficulty with this interpretation is the high frequency of residues adhering to the outside of the vessels (see table 1). These may be residues from spillage or boiling, but their location on the exterior surfaces means that the relation between the vessel contents and the crust is not a direct one." (see page 46)

If you have enjoyed reading this and would like to discuss any of the issues, please comment below. 

Saturday 20 November 2021

Beerstone is not calcium oxalate and calcium oxalate is not beerstone

This is Graham Dineley writing this blog. All ideas, opinions and mistakes are entirely my own and my responsibility. I welcome comments, please feel free to do so. 

Why am I writing this blog about beerstone? Because it is the one hard, certain and unequivocal piece of evidence for brewing beer in any era. Techniques may vary, but the fundamental processes of turning barley into beer remain invariant, they are dictated by the biochemistry of grain growth. This is the fundamental tenet to Merryn's research, as she states in her thesis and in her most recent publication.

As far as I know nobody has inspected any British prehistoric pottery for traces of beerstone yet. Maybe it is because they do not know what beerstone is, or maybe they have never considered it as a possibility. It could be a useful and productive investigation. Beerstone is robust enough to survive scrubbing, whilst organic residues are not. In fact, it should even be easier to to spot the traces of beerstone on older sherds from those days when scrubbing was a routine operation. 

A recent discovery at the Ness of Brodgar presents an interesting example for analysis for beerstone. A sherd from a Grooved Ware pot has linear parallel striations on the internal surface. The archaeologists and pottery specialist are baffled. 

Why am I discussing barley and not cereals in general? It is because I have, so far, only worked with barley malt and therefore I know only about the fermentation of barley malt causing beerstone.

I have been brewing traditional British cask conditioned ale on a domestic scale, according to Dave Line's wisdom, from his "Big Book of Brewing" for nearly 40 years now. I started with making about 5 or 6 gallons (imperial) at a time from all malted barley grain and have progressed to 10 gallons, the limit of my current mash tun. I feel that I now have some experience and expertise. I have been doing it for long enough to have made most of the possible mistakes and to have learned something from them.

I use modern equipment, plastic and stainless steel for my vessels and electricity for heating, but we have demonstrated the principle of making malt sugars from malt with a wide variety of techniques in our research. However, we have not and do not make our own malt because we have neither the resources, the facilities nor the experience to do so reliably. It is a very skilled process in itself. I rely upon commercially made malt, as I also rely upon commercial yeast. This is to avoid some of the uncertainties of beer production.


In this post I am, of course, referring to the brewer's beerstone, and not the fine limestone that is quarried from the caves behind the Devonshire town of Beer:


Any experienced brewer has encountered beerstone in the course of their activities. It is a robust precipitate of a complex of proteins and amino acids, which lock crystals of calcium oxalate into the matrix. It is a pale brownish pink in appearance, a little like hen's egg shells in texture.


Beerstone can be a problem to modern day brewers as it can harbour bacteria. It can also contaminate equipment and cause problems for further brewing and storage. It is notorious for doing this to aluminium beer kegs. It has never been a particular problem for me so far.

As far as I know beerstone is formed in only three particular circumstances, in heat exchanging wort coolers due to the heat shock, and in fermenting wort in both primary and secondary ( storage ) containers due to the carbonyl ions from the dissolved carbon dioxide. It can also form in beer dispensing lines in a public house. The precipitation process is very slow, so that a container will have to be used repeatedly for a long time to display any accumulation.

Brewing vessels and beerstone

In the archaeological literature I often read about "brewing vats" and "brewing vessels" as if there is only one kind. I have 8 different containers that I use in my brewing.

Demijohns and a siphon tube

demijohn used to drain mash tun

from left to right, sparge water heater, boiler and two primary fermenters 

New mash tun used about 15 times

The new mash tun has an electric heating element. I had to replace the old mash tun when the male steel socket pins became corroded whilst storing it in damp conditions, and would no longer make a good connection with the female plug. Note this is not a gender issue, it is the correct Electrical Engineering terminology. I couldn't find a suitable replacement element. The new mash tun is thermostatically controlled and is much easier to use. Note there is no staining, or any other marks.

old mash tun used over 100 times, note staining but no beerstone

Hamilton Bard beersphere for dispensing beer, used over 1000 times

Interior of beersphere, note beerstone

From left to right, wort transfer vessel, secondary fermenter for storage and two primary fermenters under the sleeping bags for insulation.

Inside of wort transfer vessel, note no staining and no beerstone

Inside of secondary  fermenter/storage vessel used over 1000 times, note beerstone.

The flakes of beerstone in the first illustration came from this fermenter when I scalded it with very hot water. I was trying to eliminate a persistent infection, more about this topic in a later blog. The infection was nothing to do with beerstone. It was, in fact, in the mash tun tap, which I now boil along with the mash bag before use.

Interior of a primary fermenter used about 150 times, note light accumulation of beerstone.

I replaced old primary fermenters with these new ones, when trying to eliminate that same infection.

Interior of boiler, note varnish but no beerstone.

Calcium oxalate is a completely different thing from beerstone. Calcium oxalate is virtually omnipresent in minute traces and so is no indicator of brewing whatsoever. It is present in large quantities in some plants, like rhubarb leaves, where there is sufficient quantities to render them toxic.

Prehistoric brewers did not have wort coolers and neither do I. So the only place that prehistoric beerstone will be found is in the fermenting and storage containers, as do I.

In 1993 Dr Virginia R. Badler and others published a paper on the possibilities for the chemical detection of ancient fermented beverages. As far as I know, it was the first paper on this topic and is a seminal and authoritative work. The first part of the paper is on wine. For her discussion of beerstone see the section "another fermented beverage" on page 412.

Many scholarly academic beer "experts" have never actually made beer, and so have no experience or expertise. Brewing beer is a particularly experiential process, where the subtleties and nuances are necessary and essential for the full understanding. Many of these "experts" confuse beerstone with calcium oxalate. 

Here is a link to an interview of Prof. Pat McGovern by the BeerSmith.

At 4:43 McGovern says the striations on the interior of a pot sherd "are to capture beerstone which is calcium oxalate which has a bitter and even poisonous character". They are in fact to capture yeast, so that when the pot is stored upside down, it will dry in those striations and start a new ferment when fresh wort is added. It is then a "magic pot" that spontaneously starts ferments. Those striations will however also collect beerstone over many uses. This is the sort of thing that Dr Virginia R. Badler identified.

At 7:44 McGovern says that people used to ferment tubers, which are starch rich. Lactic fermentation maybe but not alcoholic, as this requires the action of yeast on sugars, and those tubers must first be converted into sugars. How that could be done? I have no idea, and he doesn't explain that either.

At 13:53 McGovern talks of Marula fruit and drunken elephants. That is a hoary old myth. You need anaerobic fermentation to make alcohol. Rotting fruit is not alcoholic, otherwise we would be drinking rotting fruit bowls.

Finally at 20:52 he says that he has never made a beer but perhaps he should do so for the experience. I agree he should do, and he should use the traditional methods of mashing the malt in a mash tun to make the wort, liquid malt sugars. Then maybe he will know something about what he is trying to talk about in ancient brewing.

I will leave yourselves to judge the rest of his interview.

He has collaborated with Sam Calagione of Dogfish Head breweries, who use malt extracts, syrups and fruit pulp in their brews.

In his second book, "Ancient Brews", all the recipes involve malt extract and other exotic ingredients that were not available until after the industrial revolution. He collaborates with Doug Griffith, who uses the American BIAB or "brew in a bag" technique. This a method that I am unfamiliar with, and seems to me to be a particularly American tradition, where the grains are used for colour and flavour, and not primarily to produce the fermentable sugars.

It seems to me that Professor McGovern is not aware that Prohibition in America completely changed their brewing style, from all grain mashing to produce the fermentable sugars, to a largely extract brewing tradition.

Then there is the Heiss paper "mashes to mashes crust to crust". It is a fascinating paper, with some excellent archaeological examples of grain residues, but the processes in brewing are so sadly ill-informed that it is obvious that they have never made a beer. They use the terms germinated, sprouted and malted as if they refer to the same thing. They are obviously using the archaeological literature for this. There is no illustration of these things so that it is impossible to see what they are actually talking about. 

They seem to think that a few barley grains grown in a Petri dish is malt, but without any illustrations it is difficult to tell just exactly what they were analysing.

In their diagram of the chaine operatoire of brewing, they mention calcium oxalate in actions 6, 7 and 8. Chaine operatoire is an anthropological phrase and it has no place in brewing science and technology. There is so much wrong with this illustration below. Brewing beer is not a two step process. It takes at least 3 steps, 1) malting the grain, 2) making the wort, or liquid sugars and 3) fermenting that wort.

chaine operatoire of brewing actions acc to Heiss et al (2020)

Action 1: "soaking". The correct term is steeping or imbibification. The grain is a living organism and needs to breathe, otherwise it will drown. It needs oxygen and ventilation. The traditional way on Orkney is to place the grain in a sack in a bubbling stream, or if using a steeping container it needs frequent air rests.

Action 2: "sprouting". Once the grain begins to show signs of growth, after 2 or 3 days depending on the ambient temperature it is ready. "Twa Taes" is the Orcadian phrase, or "two toes". It must then be turned out onto the malting floor and turned and raked to confuse the geotropism and inhibit the growth of the shoot  for the next 4 or 5 days. Again, this depends upon the ambient temperature, and will not work successfully if the grain bed temperature exceeds 20°C. Any growth of the shoot is lost potential sugars, for that starch is lost to growth which could have been converted into sugars in the mash tun by the enzymes produced in the malting process. This flooring also allows the grain to complete germination, without growth, and for the proteolytic enzymes to degrade the protein matrix that binds the starch granules together. This make the malt friable and easy to crush when dried.

Action 3: "drying or roasting". The green malt must be gently dried at a low temperature over 2 or 3 days, to preserve the enzymes. Roasted malts have been introduced after the industrial revolution, when coke was used to dry the malt. Coke produces pale malt which has a better conversion, but the lacks the colour and flavour of traditional fuel fired kilning. Kilning can be a confusing term, because most people think of pottery kilns, which are run at high temperatures. Grain (corn and malt) kilns must be run at a low temperature, to preserve the seed corn for germination. This not the archaeological "parching". The malt must also be dried at a low temperature to preserve the enzymes for later conversion. This not roasting. 

All this was known long ago, before scientific explanations, as preserving the "spirit" of the grain, see Stopes (1885).

Nowadays these 3 stages are performed in huge, highly technical rotating drums on an industrial scale, but again the processes remain the same.

Action 5: "crushing or grinding". Malt must be crushed to preserve the husks, they perform an important role in filtering the wort during lautering and sparging.

Actions 6 and 7: "soaking and heating". These are actually one process, mashing. One easy way of mashing is to raise the water temperature to about 74°C, and then adding the crushed malt, the strike. The temperature is lowered by the malt to the desired 65-67°C and maintained at this temperature for about an hour or so for the enzymes in the malt to convert to starches into malt sugars. The harder way is to start from cold, and to slowly raise the temperature to the conversion point and then to hold it there for the hour or so.

Action 8: "fermentation". This is the only stage that causes beerstone to be precipitated.

I think that the authors of this paper would benefit from making a beer too. Then perhaps they would also understand what they are trying to talk about.

That fact that they have 197 entries in their Bibliography reminds me of the old joke about the bespoke tailor, "Never mind the quality, feel the width."  Many of them are obscure and not easily accessible.

This is not Science as I know it!



A recent paper by Oliver E. Craig discusses several types of fermentation including the potential for identifying 'cereal fermentation' on pottery. He thinks that the use of the Feigl Spot test to identify fermentation is inconclusive and controversial:

"The chemical identification of fermented alcoholic beverages is one of the most controversial areas of biomolecular archaeology, and few claims are accepted without challenge."

He goes on to say that:

"Even though, as noted above, there is no reason to dispute these claims on theoretical or contextual grounds, the chemical analysis is lacking. These claims invariably rely on the detection of calcium oxalate (a major component of “beerstone”) using a chemical spot test (Feigl 1956), which would seem wholly inappropriate considering that the test itself is not specific to the target analyte and that the oxalates may occur in many substances other than beerstone."

Since he talks of 'fermenting cereals' and not malt and malt sugars, it seems to me that he has no practical experience of brewing ale or beer or of beerstone.

If you don’t know what you are looking for how do you know whether or not you have found it?

This lack of knowledge is exemplified by our visit to a Viking age archaeological site on Orkney, Snusgar. When we asked one of the archaeologists “Have you found any evidence for brewing?”, they replied “None whatsoever.” We asked “Have you any idea what to look for?”, they replied “I haven’t got a clue.”

Dr Virginia R. Badler had first identified the beerstone on the inside surface of a pot sherd from Godin Tepe. She then confirmed this identification with the Feigl spot test.

I note that most of the entries in the Bibliography are from archaeological or anthropological literature. It is as if the archaeological community believe that the “font of all wisdom” resides entirely within their community. Archaeologists frequently talk of interdisciplinary research, but I think that until they step outside of their community and embrace malting and brewing science, they will make no significant progress in understanding and identifying the archaeological evidence for making malt, malt sugars, wort, ale and beer.

Wednesday 3 November 2021

Barm and the magic spoon. Godisgoode. ( part two )

This post is written by Graham Dineley, the brewer. The opinions, mistakes and misunderstandings are entirely my own, and I welcome corrections.

What is our research all about? Well the clue is in the Latin name for brewer's yeast "saccharomyces cerevisiae", a sugar fungus of beer. Only sugars can be fermented into alcohol, not starches. Cereals can be tricked into digesting themselves into malt sugars by malting and mashing. Malting is the careful and skilful controlled germination of the grains. Mashing is skilfully providing those malted grains with hot water so that their enzymes can complete the trick of saccharification, making sweet liquid wort. Anyone who talks about making ale or beer and does not mention those sugars is missing something crucial, the key ingredient. These malt sugars in themselves are very palatable and attractive and this is why the "first farmers" grew cereals. For the sugars. Once you have those malt sugars then alcoholic fermentation is an inevitable consequence and this also attractive.
When this post was first started nearly five  years ago, I thought I knew a little bit about yeast. Then things happened that made me realise just how small that little really was. I picked it up again in March 2020, but never got around to publishing it yet again. Procrastination. So I must also update this prefix.

Brewing historian Lars Marius Garshol discovered kveik. Follow this link to read more about Norway's now famous farmhouse yeast, it's a great article by Claire Bullen on the Good Beer Hunting blog.

He also discovered the kveik yeast ring, which is the "magic spoon" on steroids.

These can now be bought from my favourite "goods" supplier The Malt Miller.

Back then I had looked forward to working with kveik. It seemed to have the qualities of my once favourite bakers yeast. 

I have now had the privilege of using two kveiks generously provided by Lars Marius: Espe #20 and Rivenes #2. I can confirm that Espe is a vigorous high temperature yeast that imbues the beer with a fruity plum like flavour. It was very tasty.

Also my favourite bakers yeast changed into a bread making yeast, and became unusable. It stubbornly refused to drop out, even after four weeks settling, the taste is still "muddy". It still does the same today and is no longer fit for my brewing purposes. I now use a commercial brewers packet yeast that has a wonderful coagulating and clumping action.

On the left is the baker's yeast, middle is bread makers yeast and right the commercial yeast. The bakers yeast changed before the packaging did. This confused me at the time.

I also looked into sourdough because so many people have said that it can be used for brewing. Mostly not, because it is a different fermentation mostly lactic, but some sour-doughs do contain Saccharomyces Cerevisiae. Sourdough is a whole other warren full of wonderful rabbit holes, if one has the time and curiosity to study it.

I am prompted to publish it now because of two recent experiments, where people have tried to recreate ancient brews and have relied upon the vagaries of "wild wind borne" yeasts. This "wind borne" yeast is an archaeological myth that will not die.

The first is the Dietrich's experiment to recreate a Gobekli Tepe brew. If you look closely you can see that their "beer" has a greenish tinge (page 17). Click on the link above to read their paper. It must have been made with sprouted grain. 

I wonder whether they managed to make any malt sugars to ferment. I'm not so sure that they did. This is another archaeological myth, that malt is sprouted grain with green shoots. For a discussion of this see my blog, where there is a picture of archaeological malt from the Plant Cult workshop on Ancient Beer. Merryn was invited to present a paper at this meeting in February 2019, however, due to illness she was unable to attend. Fortunately, she has just published an article based upon this presentation. It is called 'The Ancient Magic of Malt' and you can read it online in the EXARC Journal here.

The second experiment is a Czech scientist brewing a 3000 year old "beer", using millet and potato? starch. What no malt? So no sugars! It must be a lactic fermentation and not lambic. Wild yeasts are notoriously unreliable. The beer was sour, like lemons. Chemist Lukáš Kučera from the University of Olomouc brewed the "beer". He says of his recreated brew:

“What makes this beer specific is that it needs to be fermented with wild yeast. You cannot buy this type of yeast in a shop. That's why I purposely fermented the beer in the vicinity of apples.

“The beer has a characteristic acidic flavour that will remind you of cider or wine, rather than beer. It has the colour of beer, it smells like cider and tastes a bit like lemon.”


Both of these two experiments also rely upon the widespread misconception, or myth that it is easy to capture a wild yeast that will start an alcoholic fermentation.
I do not rely upon this myth. On the two occasions that we demonstrated mashing and have got back too late to deal with the mash that day, we have left a the mash overnight.
Both times we have found the next morning that the mash is sour and fizzy. They had become infected with a lactic fermentation. It is impossible to make a mash with primitive equipment  and keep it hygienic. To effect a decent fermentation it is necessary to inoculate the fresh wort with a vigorous yeast starter.

I am beginning to suspect that the root cause here is that there is widespread confusion and misunderstanding about fermentation. That there is only one kind, and this would lie behind the idea that one can ferment anything. There are many kinds of fermentation, but the two most commonly encountered are lactic fermentation, e.g. sauerkraut, and alcoholic fermentation, turning sugars into alcohol, e.g. wine and beer.

Professor Keith Steinkraus has written a definitive book about fermentation and here is a good paper.


So here are some random ramblings about yeast, slightly updated.

Apparently Saccharomyces Cerevisiae is a "killer" yeast, that is, it secretes toxins that inhibit the growth of other yeasts and bacteria. This is how it can predominate given favourable conditions. How it does this is fascinating.

How it replicates is even more interesting. It has two forms, haploid and diploid. Both forms normally replicate by mitosis, they bud daughter yeast cells. Under stress, e.g. drying, the haploid form normally dies, but the diploid form sporulates, that is it produces spores. These spores can then mate to provide new yeast cells and this gives it the chance to hybridise with other yeasts. This doesn't happen very often, but it can lead to new strains and varieties with different properties.

From wikimedia.

The spores can be wind and air borne on dust and insects. This became obvious to me in our last house in Manchester. After about 12 years of brewing and washing equipment there, any sweet juice drinks left out overnight by the kids in the summer months would be slightly fizzy by the morning, as did any yoghurt.

It was obvious to me that the yeast had established itself in the microbiome of the house, along with 130 years worth of other micro-organisms. This sort of thing must happen in every brewery, no matter how much attention is devoted to hygiene and sterility.

Airborne yeast.

Recently I was listening to a radio interview about the archaeological discovery of the earliest physical evidence for beer in Britain, a fourth century BC site by the A14 near Oxford. Apparently examination of carbonised cereal residue found "micro structures of remains had changed through the fermentation process and air bubbles are typical of those formed in the boiling and mashing process of brewing". What!? This makes absolutely no sense to me, the processes are in the wrong order. Where did they get this from? Did it come from the academic literature, or did they just make it up, or perhaps both?

The beer writer said something like "It would have been a wild yeast. It would be wind borne, and so it would taste like this Belgian Lambic Beer".

I thought to myself, that is three naive assumptions in a row.

1) I would never trust the vagaries of the wind to get the right yeast. These people should know how to manage yeast if they were making beer regularly.
One thing learnt from our ancient brewing research is that if one uses "rustic" methods to make a wort, it is already heavily infected with all kinds of things, mostly various lactic bacteria. If one is making raw ale, that is unboiled ale, then one has to quickly overcome these infections with a vigorous ferment.

2) The Belgian Lambic beers are air inoculated, not wind inoculated, as is shown by the Cantillon brewery. When they refurbished their brewery with a new roof they found that the open wort would not ferment, like it used to. They had to put some of the old roof tiles back into the roof fabric to maintain the ferments, so the microbes are coming from the building and not the wind.

3) That particular Belgian flavour of beer is a local tradition and is not universal.

Windborne yeast.

In the late 80s I was following an American e-mail brewing discussion list digest. I was surprised and intrigued by one post. A brewer had visited a Founding Fathers re-enactment settlement, and he spotted a hop plant. When he asked what it was for, the lady replied that it was to make hop-tea to capture the right yeast for making bread. This means that there was a pre-existing Saccharomyces Cerevisiae in North America, suitable for both baking and brewing before brewing had been established there. I have heard that this was a common practise in North America, particularly on the West Coast, until the advent of dried yeast, and the rail-roads.
Perhaps this was a close relative of S.C. Californiensis that is found in some sourdoughs.

It is an experiment I have often thought about, could I capture the right yeast here on Orkney with a hop tea.


In 1980 I was still living in shared accommodation and for convenience I was making beer from kits. At work we had a retirement celebration for some colleagues and one of the refreshments was a polypin of Pollard's Ale. Beer writers and bloggers Boak and Bailey have written a blog about Pollards.

Pollard's beer had a very distinctive, dry almost musty flavour, that was very popular. At the end of the celebration there were a few pints left with the lees ( sludge at the bottom). So I took it home and added it to a 5 gallon kit brew that had just finished primary fermentation. I expected it to settle out, but instead it took off with a very vigorous fermentation and a strong sulphurous aroma that lasted just over a day. The Pollard's was obviously metabolising something that the kit yeast had not. The resulting beer had that distinct Pollard flavour too. I have often wondered if that was a hybrid yeast. Pollard's ales did not last that long, despite being very popular. The story that I heard at the time of it's demise was that they had lost that unique yeast, and with no back up brewery to restore it, that was the end of Pollard's. 

Saccharomyces Carlsburgensis has been said to be a hybrid of an Ale yeast and a Patagonian forest yeast, or even two forest yeasts. Another story I have heard is that it is a hybrid with a Mongolian desert yeast. I don't know, but here is a link to an early use of Saccharomyces Eubayanus:



One thing that intrigues me still is the Bronze Age practise of burying cremations in large ceramic "food vessels", because they are always found upside down. If these pots were used for fermentation, then it would make good sense to store them upside down when not in use. This would dry the yeast residues and protect them from dust, so that when reused these pots would spontaneously start a ferment. They would then be considered special, maybe even life giving, and this would make sense for a burial, a kind of sympathetic magic.