Sunday 2 February 2014

jargon: the malt, the mash & what is wort

This blog was started last year but, for several reasons, I didn't keep it up. One thing that I found tricky was learning to understand the Jargon of the Blog Page. Over recent months, I have managed to get to grips with image editing software. I did that so I could copyright my photos. Now I have to work out how to do lots of other new things, like making tabs and all that stuff. I am slowly navigating my way through the 'construction' things and 'gadgets'. See what I mean? I'm not even sure how to explain what it is that I don't know what to do! 

I am not asking for help. I know that if I persevere, I will learn how to do this. Eventually. Sometimes you need to do something for yourself before you can say that you understand it. So far I have mastered quite a few 'computer things' and this blog is just another. 

The point I want to make is this: that every skilled activity uses jargon to explain the specialised knowledge, skills and tricks of the trade. Once you learn the vocabulary, the jargon, the particular methods and techniques it is relatively easy to do. But if you don't understand these things, then you can be faced with a very difficult task. Every ancient and traditional craft has its' jargon. Those of the maltster and brewer are no exception. 
the jargon of malting and brewing - well some of it anyway 
Much of the jargon used by maltsters and brewers can be misunderstood by non brewers. It can lead to some very odd conversations between brewer and non brewer. I once spent a long time talking to someone about the possible archaeological evidence for malt and ale, only to discover later that he believed that I was talking about whiskey and ale. I thought it was a strange conversation at the time. Below is a picture of part of what I was talking about. 

Traditional floor malting. Not one of my photos, this one was given to me by Ivor Murrell, who was Director General of the magb between 1993 and 2006. The malt is raked as it begins to germinate on the malting floor. 

I was talking about 'malt' as in malted barley, partially germinated grain, the prime ingredient for ale, beer, lager and also whiskey. Malt is grain that has been steeped in water, then it is spread out on a smooth floor in a dark, well ventilated building to begin to germinate. It must be raked and turned, to stop the rootlets from becoming matted together, before being carefully dried in a kiln. Malting is an ancient craft. A complex craft. One that probably dates back to the earliest grain processors of the Fertile Crescent, over ten thousand years ago.

Another example of brewer's jargon is 'to mash' or as we call it in our garage brew house 'to run a mash'. We call it 'running a mash' because that's what it feels like. In modern breweries, the temperature of the water is regulated electronically. Or by computer. In our garage brew house, we have a simple mash tun that is heated by an electric element and you have to watch over it very carefully, turning it on and off as needs be. The mash tun is where the crushed malt is mixed with hot water (not too hot) and then left for about an hour. It is not like mashing potatoes. Nor is it like treading grapes ...

crushed malted barley is added to hot water in the mash tun

It is important to crush the malt before adding it to the hot water in the mash tun. We now know that, at temperatures between 65 and 67 degrees Centigrade, the enzymes (amylase) within the malt are reactivated in the hot water. They convert, transform or hydrolyse the grain starch into malt sugars. The technical term for this is the saccharification.This is what happens in every mash tun, whether it is a modern one heated by electricity or an old fashioned one, for example a cauldron heated by a fire or a wooden tub or trough heated by hot rocks. 

We ran a Viking style mash in a wooden tub and we got a good conversion of starch into sugars, using hot stones to heat the water and the mash. First of all, you have to heat the water to the correct temperature before you add the crushed malt. This is when you can see your face most clearly reflected in the hot water. Modern brewers use a thermometer. Before they were invented, brewers used this traditional technique, and it just so happens that, at 74 degrees Centigrade, the water becomes still enough to see a reflection. Hotter than that and it becomes too steamy to see anything. Cooler than that and the water surface is too 'bumpy'.

Add crushed malt to hot water, maintain the temperature for about an hour and then lauter and sparge to obtain a wort. This involves running off the sweet wort from the mash tun (lautering), collecting the wort in a clean jug. The cloudy wort is poured through the mash until it runs clear, and then you can sparge, by gently pouring hot water through the mash to obtain several gallons of wort (sparging). The grain itself acts as a filter. The wort is boiled with herbs or hops and then, when it is cool enough, yeast or barm is added which ferments the sugars into alcohol. Barm is the foam on the top of a fermenting beer and many craft breweries 'harvest' the barm and use it to start new fermentations.

We usually use about 13lb of pale crushed malt and we get 6 or 7 gallons of wort. Recently, we made a Juniper Ale for Yule, and we added a handful of berries, a couple of ounces or thereabouts, to the boil as well as the hops. There are some photos on my Facebook page here. We sent some bottles down to the Experimental Archaeology Conference, at Oxford University in January 2014 and there are some tasting notes here.

What is wort? Wort is the sweet, dark brown liquid from the mash tun. It is what the brewer ferments into ale or beer. It tastes very sweet and it is the primary fermentable sugar for either ale or beer. Oh, and whiskey as well. 

Well, that's all for now. There is so much to be said about malt, ale and beer in prehistory and in historical times that I am sure there will be more from me soon.

My published papers and my Master's Thesis, "Barley Malt and Ale in the Neolithic" which I did at Manchester University in 1998 are available as free downloads on my page. Here. It was published as a BAR (British Archaeological Report) in 2004.


  1. Thank you for the best explanation of the "see your face" rule I've seen - I had read that it was to do with the refractive power of the water at the point it hits the right temperature, this being the point at which it best acts like a mirror, but I could never work out how that was supposed to work.

  2. This mirror effect is another of the "magic" properties of water, it is the only common substance whose solid floats on the liquid. The maximum speed of sound through water is at 73.8C, this is due to the arrangement of the molecules at this temperature and this affects the surface tension giving the smooth nearly ripple-free surface.