Monday, 13 April 2009

Decoction mashing in the UK

The sun is shining, the birds are singing, the flowers in the garden are blooming. It must be time to return to decoction mashing. This time a British description, from the 1920's.

The source is a book I bought recently, "Practical Brewing and the Management of British Beers" by WH Nithsdale and AJ Manton, published in 1924 (pages 41-42).

"Decoctioon systems are designed to secure the maximum extracts from malt. They have an economic value in the production of mild beers and running ales, but they are far from popular, one of the more common complaints being an unpalatable "husky" flavour in the finished beer.

In simple decoction two and a half barrels of liquor per quarter of malt are employed, an initial heat of 125º Fahr. being the brewer's objective. Liquor goods stand for forty minutes only, after which the turbid worts are run off without thought of the care that must be given to the brilliant taps in the infusion system. In a suitable vessel, preferably commanding the mash tun, the worts are raised to a temperature between 195º Fahr. and the boiling point, and then returned immediately, through the mashing machine, to the good in the mash tun and thoroughly roused. A temperature of 150º to 152º Fahr., may be anticipated, and by underletting boling liquor the goods temperature is raised to 154º Fahr. The goods then stand for one hour, and bright worts are run off into the copper for the usual process of boiling with the hops."

So decoction is suitable for brewing Mild. Funny they should mention that. One of the experiments Barclay Perkins made in their lager brewery during WW I was a decocted Mild.

Does decoction mashing fascinate you? Then buy a copy of "Decoction!". The best book on historical decoction mashing published this year.


MentalDental said...


How bizarre,

I was going to email you today about Nithsdale and Manton. Lots of description of mashing techniques and also quite a bit about strengths and taxation between the world wars. I wondered why you hadn't mentioned it before, and now I know!

Old brewing books are all so different, many emphasing one topic that the next ignores. De Clerck, for example, is full of technical laboratory information but there isn't a sniff of a recipe. Nithsdale and Manton seem obsessed with taxation, but then the three editions span 1913 to 1947 so that is, perhaps, no surprise.

Aaron Bennett said...

Did I read that right? They boiled the wort, not the grain?

Aaron J. Grier said...

I'm about 100 pages into Ron's decoction book, and at this point I'll believe brewers have tried just about anything regarding decoction. boiling the early runoff (satz?) would surely dissociate a lot of the enzymes, (and break down other proteins?) but there might be enough left in with the grain to get conversion. this isn't berliner weisse where half the grist has no diastatic power at all...

who needs crystal malts when you can just create dextrins from your base malt with a reverse decoction?

maybe I'll have to try this next weekend.