There were twelve tickets available. Malt, malting and the history of the craft is something that I'm particularly interested in, so I bought two tickets on the first day that they were available. Well worth it. The second presentation of the morning, by Distillery Manager Marie Stanton, was about the practice and techniques of floor malting. She gave us a fascinating insight into the craft.
To make good malt, she said, you need good quality barley as well as common sense, experience, commitment and an unnatural obsession with the weather. The first four things seem obvious but, the weather? What's that got to do with making malt? Malt is a living thing, it requires careful handling and processing. The maltster needs to be very much aware of the weather, looking after the barley on the floor as it begins to germinate and adjusting things accordingly. In cold weather, the barley is couched, or heaped up deeper on the floor. In warm weather, such as the day the seminar was held, they had been raking it out thinner, to cool it. The grain generates heat as it germinates on the floor.
This is the ancient craft of floor malting, a craft that has been around for thousands of years. Decisions about length of steep, depth of bed and readiness for the kiln are based upon years of experience, knowledge and skill.
The steep is about more than just getting the barley wet before it goes onto the germination floor. Water temperature is important, as well as several air rests. Grain left in water will drown and be no good for germination. The idea is to rehydrate the harvested and stored grain up to about 45% moisture.
When sufficiently steeped, the grain is couched, spread, turned and raked regularly according to temperature and conditions. It begins to germinate. This might sound straightforward, but there's more to it than you might think. I'll write about this in the next blog, the tour of the Maltings. When we were visiting, malt was drying in the kiln but there was none on the floors.
|steeped grain on the malting floors at the Highland Park Distillery, Kirkwall, Orkney
source: undiscovered Scotland where there is more about floor maltings
The presentation on Making Malt continued. Bowls of barley were passed round.
One contained freshly steeped barley. It had the aroma of wet grain, as you might expect. Another contained barley that had been on the floor and had begun to germinate. This had a pleasant, fresh, almost floral aroma which is hard to describe. The two bowls had very different aromas, although they were just a couple of days' processing apart. This was something I did not expect, these aromas of germinating barley.
There is some complex chemistry going on inside the grain as it begins to germinate. If you want to know more about the biochemistry and physiology of grain germination, there's a reading list at the end of the blog.
The purpose of germination is to allow the embryo to grow, just a little. Enzymes develop and begin to degrade the beta glutens, proteins and cell walls. This is known as modification. When the grain (green malt) is sufficiently modified, it's ready for the kiln.
The malt is dried slowly and gently, to preserve the enzymes. They will be needed in the mash tun. Although there is a fierce fire, the malt is not put directly above it. Hot air and smoke from the fire needs to pass along the flue and through the bed of malted grain, drying it gently over several days. The malt steams as it dries. Both peat and coke are used as fuel. The wet malt takes on flavour from the peat smoke. It's turned regularly in the kiln, to ensure an even drying process. The maltster does not want the malt to be too dry, does not want roots, but they do want plenty of enzymes. It's important to know your kiln, we were told. Each one is different and the drying of the green malt from the floor is a matter of great skill, experience and knowledge.
After kilning, the malt needs to rest for a few weeks before it is used. There was some discussion in the room about why this should be and why it affects the flavour. It seems that the complex chemical processes of this resting period are still not understood. There was general agreement that rested and unrested malt should not be mixed together.
At the end of the presentation, a bowl of the finished malt was passed round. We were told that we could have a taste.
It was delicious, each malted grain imbued with a peaty, smoky aroma, very good indeed.
Next, the tour of the maltings. We saw bubbling steep tanks, malt chariots and shiels. We saw the malt, steaming in the kilns. As we went in I realised I'd forgotten my camera. I made notes, not just about what we saw on the tour, but also some thoughts on origins of this ancient craft and the potential archaeological evidence for it.
After completing my Master's in 1999, I tried to get funding for a PhD looking into the history and prehistory of malting and the archaeological evidence for malt. I didn't get any funding, but I did get to spend several years preparing funding applications. I worked with brewing scientists and therefore I had access to their library at UMIST, Manchester, where I read up on malting and brewing science, grain germination physiology. I can't say that I understand it all but I learned a lot.
Here are a few books that cover the subject in detail:
Bewley and Black 1994 Seeds: Physiology and Development
This is about all seeds, see the chapters on barley, barley germination, malting
Dennis Briggs 1998 Malts and MaltingThis is what maltsters call “the bible”.
D E Briggs, R S Stevens, Tom Young, J S Hough 1981 Malting and Brewing Science: Malt and Sweet Wort, Vol 1, Springer US
There is a second volume on hopped wort and beer.