For my next brew (a Flanders Red), I plugged all of my grains (18 srm) into Brun’water along with 100% RO water using the brown malty water profile. After making appropriate salt additions (gypsum, calcium chloride) I ended up with a target mash pH (at room temps) of 5.2. After some consideration, I was thinking that this low of a pH for a sour beer would not be a big deal as it may add to some tartness in the finished product. Am I correct in this thinking or should I add some baking soda or pickling lime to bring up the pH to say 5.4? Or can I RDWAHAHB?
I dont think you will find much difference in a beer mashed at 5.2 compared to 5.4. (in practice, if I am in the 5.1 to 5.5 range at mash time, I do not see any differences) This is especially so in a beer that you are going to let lacto, pedio and brett work until the beer gets down to a PH that is tart enough.
In beers that just have a sac fermentation, the PH is pretty much set after fermentation, but with a Flanders… time will let the PH keep ticking down… and in reality, the couple points PH is not perceptable.
I’m not so sure that mash pH will translate to final pH in this case. Meaning I doubt that identical Flanders, with the only difference being 5.2 and 5.4 mash pH, would result in final pH s of, for example, 3.2 and 3.4. On the other hand, it could also be that the 5.4 might go lower than the 5.2. Someone should do an experiment on how mash pH effects final pH in sour beers.
My personal method is to make wort as normal. The boil is the same except for less hops. And with this year’s sour beers, because I now have a good meter, I will be adjusting my wort post boil, pre pitch, to 4.5. Reason being that I pitch lacto first for a week at 90 and I think that manually lowering my ph to 4.5 will inhibit anything that survived the boil or drifted in between the boil and the pitch.
You definitely wouldn’t want to raise your mash pH with an alkali addition. A mash pH of 5.2 will be OK for a beer that is ultimately going to end up as a soured beer.
So, I will let this one roll with a 5.2 mash pH. But why would I definitely not want to raise the mash pH with an alkali addition. Can you please explain this for me?
You are just adding more salts to the water via the alkali addition when you ultimately want the resulting beer to have a low pH. The alkali addition is working against your beer’s eventual goal of low pH. In fact, a high wort pH can end up slightly reducing that drop in beer pH. That may not be a preferred result in a soured beer.
Gotcha! That was what I was figuring too. Thank you for clarifying that for me.