"Slack Malt"?

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PeeBee
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"Slack Malt"?

Post by PeeBee » Wed Aug 10, 2022 10:45 am

Just what is "slack malt"?

A few years ago, I began brewing again after a 4-year break ("no fixed abode", brewing gear in storage, etc.). I'd built a new brewery and the trial run was with left over 5-year-old crushed wheat malt. The results weren't good flavour-wise, as expected. This was my only experience of what I imagined was "slack malt". But was it?

Recently I started brewing with some left-over un-crushed Maris Otter. It had been neglected while I spent time exploring heritage malts (like that made from Chevallier barley) and brewing Edwardian and Victorian beers. The MO malt was still in-date (they have a massive two-years "best-by" on un-crushed malt). I knocked up the first brew which had about 45% MO and a lot of crystal, Munich, and other "specialty malts". All the same I felt I had to chuck in 100g glucose 'cos the extract seemed low. The result was still down at OG 1.047 when I was expecting 1.051. But the finished beer tastes okay.

Second attempt; no sugar and very little "extras". it was a thirst quenching "Summer beer" and I was only expecting OG 1.040. I got 1.031.

I'm a little experienced (about 45 years at it) and this doesn't happen to me! So ... Are these painfully low extracts typical of what "slack malt" really means?
Cask-conditioned style ale out of a keg/Cornie (the "treatise"): https://drive.google.com/file/d/0BwzEv5 ... rDKRMjcO1g
Water report demystified (the "Defuddler"; removes the nonsense!): https://drive.google.com/drive/folders/ ... sp=sharing

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Eric
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Re: "Slack Malt"?

Post by Eric » Wed Aug 10, 2022 2:56 pm

I thought malt could be kept for a long time provided it was kept off the ground in dry surroundings and out of the reach of vermin. Slack malt. I believe, is malt that has absorbed moisture during storage, which in turn leads to an assumed double loss. Firstly the malt is partially degraded and secondly, containing more water, any given weight provides less dry malt.

I've changed my opinion of Hancock's, high invert, 1888 brew. It makes a wonderful shandy in hot weather.
Without patience, life becomes difficult and the sooner it's finished, the better.

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PeeBee
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Re: "Slack Malt"?

Post by PeeBee » Wed Aug 10, 2022 4:10 pm

Thanks Eric.

As replies weren't exactly flooding in, I resorted to Google (hang-on ... I'd normally do that first. Guess I was having a senior moment?). There wasn't a lot on it, just a brief article from "The Oxford Companion to Beer". Yet we all (homebrewers) know of it, do we all just guess the meaning of such an arcane term? Or was that just me?

But yes, it's the result of malt absorbing water from the air (hygroscopic, not hydroscopic, another thing I learnt from beer-brewing - concerning calcium chloride - only very recently!). Which results in degraded enzymes and low extracts. If that is what it was. For something so "contagious" - I've caught it out the blue - you'd think more is made of it? Instead, we worry about the parts-per-million of Calcium ions in our water, etc., which cannot have but the tiniest fraction of the impact that storing your malt mildly incorrectly has. (I'm on me high horse now).

Glad the "Hancock's Mild" is finding its place. I've got a modern day "Centennial Blonde" filling the same hot weather duty at this very moment. And it just happens to be the beer affected by this "slack malt" contagion. So, I can drink more of it!
Cask-conditioned style ale out of a keg/Cornie (the "treatise"): https://drive.google.com/file/d/0BwzEv5 ... rDKRMjcO1g
Water report demystified (the "Defuddler"; removes the nonsense!): https://drive.google.com/drive/folders/ ... sp=sharing

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MashBag
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Re: "Slack Malt"?

Post by MashBag » Thu Aug 11, 2022 6:47 am

Instead, we worry about the parts-per-million of Calcium ions in our water, etc., which cannot have but the tiniest fraction of the impact that storing your malt mildly incorrectly has. (I'm on me high horse now).
That is a very good point, how often to people just screw the top down yet leave the bag open or do most people buy for the fresh grain per brew?

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Eric
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Re: "Slack Malt"?

Post by Eric » Thu Aug 11, 2022 8:22 am

MashBag wrote:
Thu Aug 11, 2022 6:47 am

That is a very good point, how often do people just screw the top down yet leave the bag open or do most people buy for the fresh grain per brew?
This should only ever be a problem for homebrewers, commercial brewers won't have space to keep several months supply apart from the odd bag of black, crystal and the like they have on hand for correction when things go awry. I've enough pale malt for the next brew and perhaps another if I mix in some Vienna and Lager that is currently sitting spare, but that's because I have space to order in bulk and ultimately reduce my brewing costs while allowing e to brew something at the drop of a hat.

A small piece on Slack Malt.
Without patience, life becomes difficult and the sooner it's finished, the better.

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