We have been discussing this on another board and I want to bounce it around with you guys. I have an issue that I occasionally get on pale beers where the beer is harsh-tasting, grainy, husky, cloudy, etc. This does not happen on my amber or darker beers and it doesn’t happen on all pale beers. My process for almost all batches is to mash with 4 gallons of water which may be 50-75% distilled water and the rest tap water (Ca 34, Mg 12, Na 9, Cl 21, SO4 27, Bicarb 138), add calcium chloride and/or gypsum depending on the beer, check the pH of the mash, knock it down with lactic acid if necessary, etc. I am using a Milwaukee PH55 meter that has shown signs of not being overly reliable at times. But here’s the issue: When I batch sparge, I usually have another 4 gallons of water that have not been adjusted… no salts, no acid, etc. I add that to the MT after the first runnings have been drained and I check the pH of the sparge which may take 10-15 minutes. I heat my sparge water to 150-160°… never hotter. The time frame from adding the sparge water to the grains until I’m done recircing and draining might be 20 minutes total. Does anyone think that 4 gallons of 150-160° water with a pH between 6.6 (my tap water) and 7.0 (the pH of distilled water) being added to the pale grain bill of a helles, pils, American wheat, blonde ale, kolsch, etc. could bring out tannins that would create this character? Some brewing buds have suggested acidifying the sparge water before heating it and getting it to 5.5. I did this on a pilsner I made last Friday and it’s in primary at the moment. There might be some information I left out here but if anyone has a definitive answer for the cause of this issue, please post. I have read that excessive tannin extraction is a product of all three of these: high mash/sparge temp PLUS a ph over 6.0 PLUS some amount of time. Also… this character makes the beer anywhere from mildly unpleasant to downright undrinkable. A harsh, sharp finish to the beer, a haze that won’t ever disappear and that husky & grainy flavor. Thanks gang.
EDIT: If I measure the pH of the sparge and it’s approaching 6.0 or over it, I hit it with lactic acid but it still might take 10-15 minutes before I have that reading. Also, I have been in the habit of making sure my preboil kettle pH is in the mid 5s. So I do not boil at high pH but that sparge could be sitting at the higher-than-desired pH for the 15-20 mins.