I have been reading up on the topic and looking around for some good instructions in practice for those of us who brew BIAB Ales/Lagers.
SO i get that because the water to grain ratio for BIAB is higher then conventional sparge techniques our pH will likely be on the high side (Alkaline).
So I turn on my electric kettle bring the water temps up, add the grains, set the re-circulation pump and set my temps to sat 154F. I would normally let this run for 60 minutes.
Do I take a sample 15 mins in and adjust my pH based on that reading or should I wait till the end of the 60 minutes and before I start the boil phase to take a reading and adjust the water level?
Do I just need to make sure I have some Lactic Acid 88% on hand to lower it? Just add little at time and keep testing with the test strips? Once I am around 5.2 level, I can then proceed to the boil phase?
Thx
First, where your pH ends up is highly dependent upon your starting water. Don't assume that the pH will be high because you have a greater amount of water in the initial mash infusion. If your water, like mine, is pretty close to RO water it will have no buffering capacity and will adjust pretty quickly to reflect the pH contributions of the malts being used.
You can take a sample at 15 minutes, chill, and measure pH, then make an acid addition, but honestly, most of your conversion will be done by that time. You can make an initial adjustment and then use that amount to adjust your water the next time. I usually take a final pH sample and reading at the end of the mash and while the wort is heating up to the boil so that I can make any adjustments for the next brew session. I have generally found that if I start somewhere in the 5.0 to 5.8 pH region at the start of the mash, it will be pretty close to 5.2 to 5.4 by the end of the mash.
Making an adjustment after the mash is over doesn't help in improving enzyme efficiency since most of the enzymes are denatured or will be soon as you are raising the temperature of the wort. I've read several articles on the effect of wort pH on the ending flavor of the beer, but honestly cannot comment on what affect and to what degree it does.
You can have some lactic acid on hand to make adjustments, but if you are in the prime range of 5.0 to 5.8, I would not recommend trying to adjust it. I use mineral salts to adjust my water which I add the day before and have not used acid for pH control in years. If I find that I am off from my target or estimated pH, I make a note to adjust for the next time and keep brewing.