Adding Acid to Lower pH *During* Fermentation

[reidmangan@gmail.com]

I've got an IPA fermenting – WLP001, OG of 1.065. Mash pH was 5.27, boil pH was 5.32.

After 4 days in the fermenter at 68ºF, I'm down to 1.016. However, my pH is a little high at 4.55. Wort was aerated well with O2, yeast was pitched from 1.5L starter using 2 packets. Fermentation has been strong.

Two questions:
1. Has anyone added acid during fermentation to bring it to the 4.2-4.3 range? I've read a few threads where people add it to the serving keg, but I'm curious if there are benefits to managing pH while fermentation is going on. IE, for a better microbial environment.

2. The beer is highly hopped - 8oz during boil. I've found that in some of my other highly hopped beers, fermentation pH is on the higher end. Is there any relationship here? For context, I typically mash in the 5.2-5.3 range. I have a Saison and a Stout – lightly hopped – also fermenting. Both are at 4.25
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Thanks!

 

[jeffpn]

I didn’t know people checked pH during fermentation.

 

[Nosybear]

I wouldn't. If you didn't have the pH you need going into the fermentor, it won't matter much to the fermentation to adjust it (pH affects extract and clarity, not yeast performance, and the couple degrees isn't going to affect other microbes much). Wait until fermentation is done, taste the beer then if necessary, add acid to taste. I'd look at color more than hopping for the pH variance you describe, or maybe OG - it stands to reason if you have more OG, your yeast will produce more acid over the course of the fermentation.

 

[reidmangan@gmail.com]

I didn’t know people checked pH during fermentation.

Maybe it's strange, but I always have.

After 3-5 days of fermentation I pull samples every couple of days to just see how things are progressing/capture data. I take a gravity, temperature, and pH reading.

My experience with most beers is that pH drops to the low 4's pretty soon after yeast is pitched, and a healthy fermentation will stay there for the rest of the process. Large increases in pH can be signs of unhealthy yeast or infection. 4.5-4.6 is still in ballpark, but can contribute a bland/salty taste. I have added acid to the serving keg with good results. I'm wondering if there's any benefit to being a little more proactive.

 

[reidmangan@gmail.com]

I wouldn't. If you didn't have the pH you need going into the fermentor, it won't matter much to the fermentation to adjust it (pH affects extract and clarity, not yeast performance, and the couple degrees isn't going to affect other microbes much). Wait until fermentation is done, taste the beer then if necessary, add acid to taste. I'd look at color more than hopping for the pH variance you describe, or maybe OG - it stands to reason if you have more OG, your yeast will produce more acid over the course of the fermentation.

Thanks for the reply.

What's interesting – to me, at least – is that I did have the pH I needed going into the fermenter. Color is definitely the most important factor affecting pH, which is why I use it to calculate my mash/sparge additions.

Wouldn't it also stand to reason that if yeast produce more acid with a higher SG, then my pH would be lower with a beer starting at 1.065?

 

[HighVoltageMan!]

WLP001 is a Chico strain and Chico strains are not known to be high acid producers. I have check pH of final beer and I have found that 1056, US05, WLP001 usually finish with a fairly high pH, 4.40-4.60, even if the pH 5.2 at pitch.

So I usually don't use these yeasts anymore because of that. Wyeast 1007 (German Alt) is a good acid producer and makes a crisper, cleaner pale ale. Ph lands around 3.9-4.1 and bitterness is smoother, in my humble opinion.