Best method to drop PH of finished beer

[MaCheFai]

I have an IPA that's just about ready to move to serving. In doing one of my last readings (FG and PH), I noticed the PH is at 4.6, a bit higher than where i'd like it.

Is there a calculator somewhere, similar to bru'n water or brewersfriend, I can use to determine how much lactic or citric I should add to drop it 0.3 - 0.5?

 

[auburntsts]

I'm curious as to what you are trying to achieve with a specific pH for a finished beer? This is the first time I've read about pH manipulation outside of the mash so I'm totally ignorant on the subject--is there a published range for the various styles?

 

[MaCheFai]

Depending on beer style and target flavor profiles, it can be helpful to alter the finished PH to achieve your goals. In my case, I'm looking for a crisper finish to my IPA and am looking to get it close to 4.0. Rather than trial and error, I was hoping to find a calculator to measure my acid based on my recipe, volume, etc.

So I was hoping there would be something similar to one of the water calc's out there, but for finished beer. Or, better understand how to use one of the online calc's can help.

 

[cire]

pH of finished beer is usually 4.5 to 4.5 for larger and 3.9 to 4.0 for British top fermented beers. The higher pH is very likely a product of the yeast used.

 

[MaCheFai]

I'm not looking to determine why it's at 4.5, as it's fairly in the range. Rather, I'm trying to figure out how much acid I need to add in order to drop it to where I would like it.

 

[ajdelange]

Depending on beer style and target flavor profiles, it can be helpful to alter the finished PH to achieve your goals. In my case, I'm looking for a crisper finish to my IPA and am looking to get it close to 4.0.

I can see why you would like a crisper finish but I don't see how you can be certain that a pH of 4.0 is going to insure that. It seems rather obvious that the approach to take here is to add a little acid to the beer and taste. It is taste, ultimately, that is going to determine whether the beer is 'crisp' enough or not. You should, of course, record the pH values in your tasting notes. Then there is the question of which acid is going to be used. Lactic add lovely notes to beers as is well known whereas phosphoric will change the pH without much if any flavor contribution from the acid itself. Thus you will have to perform at least two sets of tests. Be sure to decarbonate before measuring pH.

Rather than trial and error, I was hoping to find a calculator to measure my acid based on my recipe, volume, etc.

As is discussed in another thread you will need to determine the buffering capacity of the beer. I have a faint recollection that it is about 31 mEq/L•pH but don't rely on that. Do a titration. Once you have the buffering it is trivial to compute the acid required as A = Volume_of_beer*desired_pH_shift*buffering. A is in mEq.

 

[mabrungard]

I wouldn't assume that a specific pH target is what you need to hit. As you're probably aware, beverages like cider, wine, and mead have Titratable Acidity goals that help define drinkability and flavor. Beer likely follows suit. But even with that said, I doubt there is a single TA or pH value that would create a desirable beverage. It is probably a range.

With that said, I've performed post-fermentation acidification and can report that the pH drop vs acid addition does NOT follow the results obtained in Bru'n Water. Apparently the buffering available in beer is more resistant to pH change than for wort. I found it took about 3 times the amount of acid to produce an equivalent pH drop in beer compared to that calculated by Bru'n Water for wort.

But even with that result, I recommend that you evaluate acid additions by adding and mixing acid to a known volume (glass) of beer and assess if the there is improvement in beer perception. You should find that there is a sweet spot where you've added enough. You can then scale up that acid addition to the volume of beer in your keg.

 

[MaCheFai]

But even with that result, I recommend that you evaluate acid additions by adding and mixing acid to a known volume (glass) of beer and assess if the there is improvement in beer perception. You should find that there is a sweet spot where you've added enough. You can then scale up that acid addition to the volume of beer in your keg.

Thanks Martin. I was hoping you had a secret tab on your sheet that I didn't know about! I was thinking of taking that route if there wasn't a more precise calculation I could make.