a morning with maltsters, part one

The Orkney Science Festival is held annually. It's always a great week of varied and interesting events, talks, demonstrations and fun. This year there was a Malt and Malting seminar with a special tour of the Maltings at the Highland Park Distillery, Kirkwall. There were only a dozen places available and we were lucky to get tickets. We spent a fascinating morning with malting, brewing and distilling experts. It was all about the malt.

Making the malt for brewing and distilling is exactly the same process. The difference in processing techniques happens after the mash tun. A brewer takes the sweet liquid from the mash tun, calls it "wort" and adds hops or herbs, then ferments it into beer or ale. The distiller takes the sweet liquid, calls it "the wash" ferments it into alcohol and then distils it. The wort and the wash are two names for the same thing, the sweet liquid that is obtained from the mash tun. Every brewer who makes ale or beer from the grain knows what wort is because they work with it. People who have never made an ale or beer from the grain are perhaps a bit confused about what it is.

wort or wash?
Depends if you are a brewer or distiller.
source here

Dr Tim Dolan gave the first talk of the morning, explaining the fundamental aspects of what malt is, the biochemistry of malt, how it is made and a little of the history and development of the industry. His career in the malting and distilling industry goes back 40 years and he now teaches the subject. The other speakers were Marie Stanton, Distillery Manager of the Highland Park. She shared her knowledge of floor malting, then led us on a wonderful tour around the Maltings. The third speaker was Eric Walker, recently retired, a man with a distinguished background in all aspects of the malting, brewing and distilling industries. He talked to us about the prehistory and history of making malt and explained some technical details. They were quite a team and between them they had a huge amount of knowledge and experience of making malt.

"Malting is a process utilised by the Ancients to produce palatable alcoholic beverages: ale and beer"  (Eric Walker)

In previous years there have been talks about brewing and distillation, usually organised by the Institute of Brewing and Distilling. Tim told us that he thought it was about time there was a Science Festival event about malt, the Cinderella subject, because malt is the crucial ingredient for ale, beer and whisky. What is malt? It is grain that has been germinated under controlled conditions, then dried carefully in a kiln. Making malt has been a skill, an art and a craft for a very long time. Over the years I have given a few talks at the Science Festival. I was pleased that Tim remembered me and had been to my presentations on malting in prehistory, neolithic ale, grain barns and my most recent "Where were the Viking Brew Houses?" a couple of years ago.

The advent of the combine harvester in the 1940s transformed the grain harvest. The ancient and traditional way of harvesting grain by hand was extremely hard work, it was a time when the whole community worked together to bring the harvest home. On Orkney, where I live, grain was harvested by hand and stacked in stooks in the field until as recently as the 1950s. In case you don't know what a stook is, I looked online and found this painting by British artist Heywood Hardy (1843-1933). Painted in 1872, it depicts a typical scene of the time. I like the detail of the stook and you can see how they were made. The effort and hard work involved in making them can only be imagined.

 Corn Stooks by Bray Church by Heywood Hardy (1872) see here

This oil painting was done just a few years before Henry Stopes published his book about Malt and Malting, an Historical Scientific and Practical Treatise in 1885. It is now available to read online. Oxford University took the trouble to scan it in, many thanks to them for that. I first read it when I borrowed a copy from a brewing scientist when I began my research. It's such an important book and it is an excellent snapshot of the malting industry in the late 19th Century. Henry Stopes mentions the work of Louis Pasteur, who had recently published his work on Germ Theory which was to make such a huge impact on the brewing industry.

But I digress. Let's get back to the talk about malting.

Tim explained the biochemical processes of germination, with the embryo being the living part of the grain and the endosperm being the starchy food store. Malt, he said, is a living thing. It must be handled and processed carefully and correctly by the maltster. This was a point that was made several times throughout the morning. First, the harvested grain is steeped in water. It's crucial to allow air rests. The steep tank is drained of water at regular intervals. If the grain is left in water without air rests it will drown and this means that it will not begin to germinate.

Thanks to scientific research into grain germination physiology and biochemistry which began in the 1960s, we now know that when grain is  sufficiently wet and aerated, gibberellic acid is released from the embryo and the aleurone cells. This stimulates enzymes which convert the grain starch into sugars, the food source for the plant.

All grains can be malted. Barley is considered to be the best grain for malting but wheat, rye and oats can also be malted. Here's a useful diagram of the internal structure of a barley grain in the early stages of germination.

The craft and skill of the maltster lies in getting the grain to start growing, but not too much. This is known as modification and there is some excellent and detailed information about what malt is and how malt is made on the Maltster's Association of Great Britain web site.

The Highland Park has three traditional malting floors where the grain is spread out after steeping. Raking and turning the malt is a crucial part of the process. We were told that this helps to maintain an even temperature and it also prevents rootlets from tangling. On the malting floor the barleya malted barley grain more details here begins to germinate. When the maltster sees the root and shoot being about four fifths the length of the grain, it is sufficiently modified and ready to be carefully and gently dried in the kiln.  a malted barley grain more details here

Modern techniques of making malt involve the use of Saladin boxes and drums. There are also huge germinating kilning vessels which can make three to five hundred tons of malt at a time. All year round. The quality of the malt can be controlled because it is easy to maintain precise temperatures and levels of moisture. The third speaker of the day, Eric Walker, gave an interesting talk about the industrialisation of malting and I'll write that up later. In the meantime, here's something I wrote about where the malting floors have gone.

Barley is self pollinating. Dr Tim Dolan emphasised this several times, but I wondered why was he making this point so many times? It was because it's so significant in understanding barley breeding. There were not so many varieties of barley in the past as there are today. The science and practice of cross breeding barley began at Warminster Maltings in 1904. This was news to me. Rather than tell you the story myself, here is the account from the Wiltshire Community History web page:

"The most famous name in local malting was that of Dr. Ernest Sloper Beaven, and his reputation is international. He was born in 1857 to a Heytesbury farming family, who moved to Boreham Farm at Warminster in 1868. Beaven said that he began to observe barley closely from 1878 and he became associated with Frank Morgan, Warminster’s leading Maltster. Beaven’s first experiments had been with onions and potatoes but from 1900 he was growing, selecting and crossing barley from seven initial different ‘races’. In 1904 he acquired fields on the Boreham Road for a nursery and in 1914 he launched ‘Beaven’s Plumage Archer’ strain of barley and continued with seed trials for the next 27 years. Beaven could claim that 85% of the total U.K. acreage of barley was grown from the progeny of just four plants, three of which had been selected in the nursery at Warminster between 1900 and 1904."

In the last one hundred years or so, much has been learned about barley and the biochemistry of germination, however, there is still much to be learned. Although some of the mystery and magic of malting has been studied and explained by scientists, some things about barley are little understood.

One of these is latent dormancy. Someone in the group asked about this and the answer was that it is still a bit of a mystery. There is a practical tradition of leaving the grain for a while between harvest and steep, because it will not germinate. This could be about variety, or it could be seasonal. The best thing I can suggest, if you are interested in finding out more about latent dormancy, is to search for the academic and scholarly papers on it. There are quite a few of them out there.

The next talk was about the skills, techniques and practicalities of floor malting and the turn of Marie Stanton, Distillery Manager, an experienced maltster at a number of distilleries. And then there was the tour of the Maltings.

There is only so much detail that one blog post can take, so I shall leave you with a picture of the malting floor at the Highland Park Distillery, Kirkwall, Orkney. It is taken from Wikimedia Commons. I forgot to take my camera to the seminar, but I did take plenty of notes, so I hope this will suffice while I get down to writing part two, while it is fresh in my memory.

https://commons.wikimedia.org/wiki/File:Highland_park_malting_floor.jpg

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

"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" 

John Tyndall FRS, extract from his speech on Fermentation, Glasgow Science Lectures Association, October 19th 1876.

Before Louis Pasteur's investigation into fermentation the whole process was a complete mystery. It was considered to be part of the "Spontaneous Generation of Life", a supernatural, magical, mystical or even divine creation. This is why one mediaeval name for it was "Godisgoode", a demonstration of God's bounty and munificence.

John Tyndall continued Pasteur's work into fermentation and helped to demolish the myth of spontaneous generation by demonstrating that micro-organisms can be carried by air-borne dust, and cause all kinds of fermentations and cultures.

We now know that beer yeast is the microorganism, saccharomyces cerevisiae, a one celled fungus that feeds on simple sugars.

http://www.microbiologyonline.org.uk/about-microbiology/introducing-microbes/fungi

In the presence of oxygen yeast can replicate rapidly through budding, turning the sugars into water and carbon dioxide, through respiration. It can double in 2 hours at 30 degrees Centigrade.

In the absence of oxygen it cannot replicate, but it can metabolise the sugars into alcohol and carbon dioxide. It isn't really happy with high alcohol concentrations and this limits production to about 10-12% alcohol.

Brewer's top fermenting yeast seems to work best, both aerobic and anaerobic, at between 15C to 25C, but it doesn't like varying temperatures and will lose condition quickly if subject to heating cycles. It generates quite a lot of heat whilst working.

I can sustain a good ferment of 10 gallons at ambient temperatures as low as 5C by insulating it with a couple of sleeping bags.

Under stress such as drying it can sporulate, and the spores can become wind-born by dust and insects.

Barm is the word used to describe brewing yeast in it's active replicating state.
The cells stick to the CO2 bubbles in the ferment and rise to the surface (top fermenting brewers yeasts) and form a foam. This is the Barm. Bread makers use this to leaven their doughs. Nowadays brewing yeasts and bread making yeasts differ, though in the past they were the same.

Barm in the brewing buckets.

This foam of yeast cells, Barm, can grow into impressive towers of rafts, and a vigorous ferment will need significant head space, or spillage will occur.

Close view of Barm.

This is how a beer brew looks after a day or two. It is at this point that the Barm can be harvested, by skimming the foam off and storing the liquid in a container. Harvested barm can remain viable for up to two weeks if it is kept cool and free from dust. Before the invention of refrigeration, a well could be used to store the barm in a warm climate. 

Brewers are paranoid about infection by a wild yeast strain or other micro-organisms, so they prefer to start a brew by inoculating the warm wort with a proven viable yeast culture, the starter. 

The starter is made by adding stored barm, or a dried yeast to a small amount of warm wort. Nowadays dried yeast can be bought, but there are traditional methods.

A good starter for pitching on the wort.

A Nordic and Hebridean tradition is to stir the barmy brew with a stick or wand, and to leave this to dry, hanging in a dry place. I've tried this and it works well. Could this be the origin of the magic witches wand?

Harvesting Barm on a spoon.

Drying spoon.

Dried yeast - barm - on the spoon

Inoculation of wort

After 32 hours at 20C.

After 48 hours at 20C.

After 48 hours from the side.

After 24 hours from the inoculation I was disappointed. Nothing seemed to be happening at all, but by 48 hours a healthy culture was established, fit for pitching.

After 96 hours.

After 96 hours.

After four days, primary fermentation is complete. It is this rapid initial doubling under favourable conditions that can make even a small amount of the right yeast into a viable starter for a pitching a good ferment.

From the moment I first started grain beer brewing I used commercial packets of dried brewers yeast. I was often disappointed by the slow or even non-existent activation for the starter. Maybe I should have been more patient, like with the spoon, but then I would have to make the starter a day or two before the wort.

Eventually I found brewing supplier who packed their own yeast which set off vigorously in the starter, giving a viable pitch in half to one hour. I quite liked the fruity and sometimes even buttery flavours.

When we moved from Manchester to Orkney I had the same problem with packet yeasts, so I had the supplier post yeast up to me. One day when I was struggling to learn how to make bread with a machine, I realised that the yeast I had become so fond of looked indistinguishable from the bakers yeast.

I now use baker's bread making yeast.

"Real Ale" brewer's yeast from a packet, left, and Baker's yeast from a tin, right.

Many breweries are very particular about their own yeasts and indeed a lot of the flavour of the beer does indeed come from the yeasts action. Some traditional recipes actually call for bakers yeast to be used. There is a very interesting article on Sahti here, and in it there is a link to a comparison of brewers and bakers yeasts.

I am beginning to suspect that the distinction between brewer's and baker's yeast only came about with the industrialisation of brewing in the Georgian era. I am certain brewing came before the leavening of bread, if not even before the invention of bread itself.

I have much more to say about yeast, microbes and infections but this post is already getting long, so there will be a part 2 to follow.