Good to find someone who knows the all malt brewing stuff. Well, I'm basing the 5kg amount to the information retrieved from John Palmer's How To Brew and whiskey recipes at Tony's website (http://arkiv.bryggforum.nu/homedistiller). As an example a bitter with 1.045 OG (5gallons) requires 7lbs of 2 row malt and 0.5 lbs of 60% caramel malt. The caramel malt in this recipe contributes very little fermentable sugars, so to scale this to 6 gals we get 8.4 lbs which is ~4.2kg. To up the OG to 1.050 or above takes ~5kg malt. If there's aproblem with this calculation feel free to point it out.ulve skrev:rkr:First of all I’m talking about the mash efficiency where conversion of the starch and collection of the sugars in the malted grains occur. Using well modified grains the typical home brewer seems to be able to achieve a mash efficiency of around 70% commercial brewers of course push this number quite a bit higher but the grain bill is usually not the problem for home brewers. To make a wort with an OG of 1.050 I have to use about 6 kg of grain (ok all is not well modified but the the lions share is). I’m also talking about the apparent attenuation of the particular yeast strain. Beer yeasts seems to have an apparent attenuation in the range from 65% to 85% which leaves quite a lot of residual sugars that gives the beer part of it’s flavour.rkr skrev:Are you talking about the yeasts ability to convert only part of the sugar to alcohol or alcohol yield from sugar by using certain yeast?
For example, I made a brown ale using 4 kg of pale ale 1.8 kg of Munich and 0.2 kg of special malts (chocolate and crystal) this gave produced a wort with a OG of 1.052. That particular time I might not have mashed the grains at peak performance but not all that bad. I used a yeast labelled with the apparent attenuation of 73%-77% (Wyeast German Ale) and the FG after two weeks of fermentation was 1.014 giving an alcohol content of 5.0 %. I also looked at some recipes for strong Scotch ale and the seem to use about 8.5 kg of grain in order to get 25 litres at 7 % all having an OG of around 1.070.
I’m not in to distilling my own whisky but I’m curious. Why settle for a “beer” with “only” 7.0% alcohol? Strong Scotch ales often have alcohol contents exceeding 8% and there seems to be no problem brewing those beers. Any particular reason?
Now the reason for lowish OG is in production of higher and lower boiling point alcohols. If the mash contains a lot of alcohol at the end of the fermenting the yeast will produce more non ethanol alcohols and also lots of other congeners some of which give unpleasant taste to whiskey. OGs of 1.070-1.080 can be used (Ian Smiley uses these in his corn whiskey book), but the higher the alcohol content at the end of fermentation the more impurities the yeast produces. There are other reasons as well (time to ferment in industrial production, risk of bacterial infections etc.), but for homedistiller the quality of whiskey is probably the main reason to use moderate OGs.
Personally I find it a bit hard to mash more than 5kg at the time while I have only 25l picnic cooler, there is very little room for more. I might actually try lautered mash next time I make whiskey. It's allways refreshing to try new approaches.
Greetz, Riku
nu är det bara att spika ihop tunnorna eken ligger snart på sågen
