Thu Jan 10, 2013 1:08 pm
Based on things I have read in the past, the water to grist ratio (e.g., 1.35 qts/lb) has very little if any bearing on efficiency, or fermentability either for that matter. If anything, it might be better to use *more* water such as 2 qts/lb, to assure all the grain is adequately wetted and thus communicating with the enzymes, not to mention that it is easier to stir, etc. I have also heard it said at Brew Strong that you don't really want to let this ratio get higher than 3 qts/lb, which most batch spargers wouldn't be doing anyway. I don't think they specified a reason why, but I can see how it might have something to do with enzyme density -- if the enzymes are too dilute, they won't be as effective in changing starches to sugars.
The exception to all this might be only for high gravity beers, where you might be exceeding 1.090 or 1.100 post-boil. If you want to maximize your efficiency with a batch sparge, then you really need to divide your water volumes into thirds and sparge not just once but twice. And in this case, you'll find that the maximum efficiency requires that you mash very thick at like 0.85-0.90 qts/lb -- at least, that is how it's worked out when I've done it a handful of times. Works great. You can still get efficiencies in the 70s if you double sparge. That is to say, aim to get 1/3 of your pre-boil volume from the first runnings, then 1/3 from the first sparge, and the final 1/3 from the second sparge. Works like a charm.
Dave
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