Okay, this may be as dumb as it sounds, but last night I set a wash of bread whisky going.
Bread whisky?
I'm glad you asked.
I've been toying with all-grain ferments using unmalted barley and enzymes — either enzymes introduced through home brew shop (HBS) γ-Amylase enzyme (a.k.a. Modiferm/AMG/'dry enzyme'/glucoamylase/amyloglucosidase), or as light malted barley (which contains various activated enzymes) at a ratio of one part malted barley to 10 parts unmalted barley. The idea is to try to make a 100% grain whisky — no sugar.
Well, last night I was pulverising the shit out of some barley in the missus' blender when I thought, "Look what you've done mate; you've just made flour". Light bulb moment.
"That's exactly right," me thinks.
You need to mill grain in order to more efficiently convert its starch into fermentable sugar. Brewers coarse mill their grain so that they can filter it off after mashing or before bottling. But we're not brewing beer, so it doesn't matter if the crushed grain is left in the fermentor to settle out. After all, we refine the contents of our fermentors, unlike those beer brewing kinds. So why not just substitute unmalted milled grain with wholemeal flour?
Off to the kitchen cupboard I go. There's a heap of old breadmaking ingredients in the bottom of the cupboard — about 4kg of old unbleached plain (wheat) flour and 1/2kg of unprocessed natural wheat bran. Both are well past their used-by dates. Sweet. Then I found 3/4 of a pack of Lowans bread improver sitting there doing sweet FA. This stuff is a mix of wheat flour, malted grain flour and amylase enzyme. Even better — something to help covert the flour starch into fermentable sugar.
Back to the shed we go.
So, start mixing things together in a 30L fermentor. After mixing 3kg of unbleached plain flour and 250g of unprocessed natural bran with a few kettles of boiling water I've got a thick slurry. I keep adding boiled water until the temp is up to 68°C — a good mashing temp.
At this point the fermentor is sitting at about 19L full. I stir in 75g of bread improver and 10 drops of liquid amyloglucosidase enzyme (MODIFERM) and let it sit there and cool, or, if you want, reverse mash.
Bugger: what's the pH?
Run a test and we're sitting just acidic at about 6.5. Optimum enzyme pH is 5.1-5.5 (see below, and here), so I add 3 teaspoons of citric acid to a glass, dissolve it and work it into the slurry. Things should be peachy now, or at least a bit better.
When the slurry gets to 40°C (5 hours) I add cold tap water to 25L. Now the temp is at 32.5°C. Near perfect.
In a small container I shake together with a bit of tap water another 75g of bread improver and 30 drops of liquid amyloglucosidase enzyme. This is just to ensure that there are living enzymes present if the early mash temp was too high for the first lot to survive. So I stir them into the mix and then whisk in 75g of Lowans baker's yeast. Seal and airlock the lid, wrap that shit in a towel and say goodnight.
She started bubbling within 10 minutes and is still going strong this morning.
Anyway, initial SG looks around 1032, but this stuff is too thick to tell. Also, if the enzymes do their job, more fermentable sugars will become available as time goes by, so an initial SG reading is going to mislead. What I need is a final %abv reading of the fermented wash.
I would have liked to have had more of a range of specific enzymes on hand — stuff that can convert starches to all kinds of fermentable sugars — but, alas, I was limited to what was in the cupboard and at the HBS. I hope the Lowans, which contains wheat and malt (malted barley) flour, brings some α- and β-Amylase to the party, but the improver is well out of date, so I don't hold out too much hope.
Because amylase enzymes are simply digestive enzymes and are present in saliva, I could always spit into the fermentor. I read somewhere that chewing barley and spitting it back into the wash was an early way to introduce additional enzymes to whisky washes. I'll hold off on the spit inoculation for now.
Comments, criticisms and predictions welcome.
:handgestures-thumbupleft:
P.S. Here's a good crash course on enzyme fermenting.