Process Question Regarding the Acidification of Brewing Liquor
I have been reading and rereading all the classic texts on brewing water and wanted to ask some fellow brewers for their opinion on proceedures for acidifying brewing liquor and if there is a preference for acidifying in the CLT or HLT and if one of them provides more consistent end results. Knowing that raising the temperature of your supply water provides minor alkalinity reduction by consuming HCO3 and acid also consumes and neutralize HCO3 directly it seems that it would be difficult to calculate how much Phos. acid to add to just the mash for instance given that your HL could vary in temperature and therefore the amount of acid you add vary by batch as your HL temp changes. If you add acid to the CLT (assuming you have one, we have to in Tejas) or inline inject acid into your supply water that would be easy to calculate how much acid to add but say for instance you are in a lower volume production facility or brewpub (like myself) where you brew 2-3 times a week and potentially have the treated CLT water, after traveling through the HE, sit in your HLT at a higher temperature for a day or two or more.
SO, Would sitting in the HLT at a high temp continue to drive off HCO3 and acidify thereby changing how you calculate your initial acid addition or would it be best to treat in the HLT prior to mashing in or is there some other way? I am curious if anyone else has been playing with ways to acidify outside of just adding it to the mash or sparge water and if these ways have or have not worked. The hope with this is to establish SOPs for our 7bbl brewhouse to maintain consistency within production. I look forward to hearing what has worked well for others on the process side!
Do it in the CLT for sure. Calcium carbonate precipitation from untreated water in the HLT (as well as the heat exchanger and pipes on the way to the HLT) will not only make your residual alkalinity a moving target, but will also be difficult to clean.
So by acidifying the Water in the CLT would you feel confident that the RA would not be a moving target even if it sat at high temps in the HLT for a couple days before being used for brewing?
If your treated water has a total alkalinity around 50 mg/L as CaCO3 (or less), which I'd recommend anyway, keeping your water hot shouldn't change its RA by any appreciable amount.
It just registered in my head that you're talking about phosphoric acid. Its temperature dependencies are beyond my chemistry knowledge, but using it to treat water - instead of adding it directly to the mash - will result in precipitated calcium solids either way. I prefer lactic acid because it doesn't precipitate any solids and it always releases one hydrogen ion under normal brewing conditions. If you're anti-lactic acid, I'd recommend that you look into slaked lime. Like phosphoric acid, it will precipitate calcium solids (which are much easier to remove from CLTs than HLTs). In fact, the removal of solid calcium carbonate is the goal and a CLT would be a great way to decant your water from it. Unlike phosphoric acid, the only byproducts of slaked lime treatments are calcium carbonate and water. Calculating how much to use won't require you to worry about dissociation constants either.
Last edited by jwalts; 06-15-2012 at 02:23 PM.