Been trying to find an answer to this everyone but can’t seem to, What is the difference between adjusting pre boil vs adjusting during boil? say for a pils, you mash a bit higher, then adjust post mash, would you still adjust boil ph? Or could you skip the post boil ph and just lower during the boil, would it be the same thing?
Not sure I’m completely following the question, but let me see if I can take a shot at it. Best of my understanding, you’re not too concerned with the boil pH, nor all that much with the pH of your water pre-boil, so long as it’s potable. Your biggest concern with pH is the mash itself, in order to facilitate enzymatic activity (among other things like beer clarity, fermentability, etc.). And mash pH will of course factor in to final beer pH. Point is, if it’s way off when you mash, it’s going to affect the beer post-boil in ways that adjusting the pH later won’t really counteract. so again, I may be misunderstanding the question, but I think if you’re going to adjust, you want to do it during the mash, not in the boil or post-boil. I’m not sure I’m aware of anyone adjusting pH during a boil, but I don’t claim to know that it’s never been done.
There are optimum pH targets for certain reactions that happen in the boil. You generally don’t want kettle full pH (start of boil) to be much over 5.4. Higher the pH the faster the conversion of SMM to DMS. So good for beers with lots of European Pilsner malt. 5.4-5.45 is sort of maximum though. Higher the pH the better the isomerization of alpha acids. However over 5.4 the harsher the bitterness becomes. There are also optimum pH targets for protein coagulation, kettle finings, as well as knockout pH values for potentially better fermentation which could lead to better diacetyl reduction and potentially a lower overall finished beer pH which has a pretty solid affect on the overall perception of the beer. Mash pH is important. Yes it can set the pH for the rest of the process. But it can also go out of whack pretty easily. For homebrewers finding an exact optimum pH for your mash isn’t really that critical. 5.3-5.5 at room temp is fine. Just remember to treat your sparge water with acid if you’re using tap. Don’t worry about it with RO, although a bit of calcium in RO sparge water can keep the final runnings pH lower which is a good thing.
