Monday 19 May 2014

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

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.

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.


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.

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