Strange Blueberry pH & Acid numbers

[saccharomyces]

Hi folks...just started a Blueberry wine, and prior to pitching my yeast, am seeing some weird numbers for both pH and TA.

I have both a handheld Hanna pH meter, which I just calibrated, as well as a Hanna mini tritrator to test total acidity, which I also just calibrated. The pH meter is reading a pH of 2.5 (!!), but the titrator is only measuring total acidity of .44. I didn't want to pitch the yeast with a pH that low as I feared it wouldn't survive, but yet if that acid level is even lose to correct, I'm afraid the wine will be too flabby. I've never seen numbers like these in any other wine I've made (low pH, low TA), so thought I'd throw this one out to the group to see if anyone else has?

 

[Stressbaby]

Briefly, what is your recipe?

 

[saccharomyces]

Briefly, what is your recipe?

Sure...19 lbs blueberries, 1.5 tsp grape tannin, around 40ppm potassium meta, Lallzyme EX-V enzyme, and enough water to bring the must level to 6.5 gallons. That's about it for now...I usually add some acid blend, but like to measure the acids and pH before doing so, and that's where I sit right now.

 

[Stressbaby]

The blueberry batches I have made most recently have started at pH 2.64 and 2.91 before adjustments. I used about twice the #/gallon you used. So although you used somewhat less fruit than I did, your pH numbers aren't all that far off. I didn't measure the TA on either one. My approach generally is to dial in the pH preferment, then adjust to taste post-ferment. In these two cases, I adjusted both to pH ~3.2 with calcium carbonate. The rosé was to be bottled dry, and so I had to use a little potassium carbonate post-ferment to bring down the acidity a little further. The regular blueberry came out lovely with just 40g/gallon sugar. I'm about to start the 2017 blueberry, and this year I'll adjust the rosé to ~3.4 preferment given the outcome from last year.

Blueberry is sort of notorious for getting stuck. Forget about the acid blend and don't worry about the TA. If I were you I would use some calcium or potassium carbonate to push the pH back up into a range where your ferment is safe. You can always add back some acid post ferment if it's flabby - it probably won't be.

 

[Stressbaby]

PS: If you have to add acid, consider straight citric or tartaric or a mix of the two, rather than acid blend, in order to stay away from the malic.

 

[saccharomyces]

The blueberry batches I have made most recently have started at pH 2.64 and 2.91 before adjustments. I used about twice the #/gallon you used. So although you used somewhat less fruit than I did, your pH numbers aren't all that far off. I didn't measure the TA on either one. My approach generally is to dial in the pH preferment, then adjust to taste post-ferment. In these two cases, I adjusted both to pH ~3.2 with calcium carbonate. The rosé was to be bottled dry, and so I had to use a little potassium carbonate post-ferment to bring down the acidity a little further. The regular blueberry came out lovely with just 40g/gallon sugar. I'm about to start the 2017 blueberry, and this year I'll adjust the rosé to ~3.4 preferment given the outcome from last year.

Blueberry is sort of notorious for getting stuck. Forget about the acid blend and don't worry about the TA. If I were you I would use some calcium or potassium carbonate to push the pH back up into a range where your ferment is safe. You can always add back some acid post ferment if it's flabby - it probably won't be.

Thanks for the info! My main concern now is that maybe I have an equipment problem, specifically with my pH meter. I had an acid test kit in my supply cabinet, so I tried that as well...and while I obviously can't get as specific a reading as using my mini-titrator, the measurement I wound up with was pretty close to what my titrator read...so that's two data points, leading me to believe he TA numbers are/were correct. The pH meter, OTOH, is all over the map. It was at 2.5, then down to 2.3, then up to 2.8, then up to 3.2. Last test was at 3.0...not sure why it would be like that, and going up on top of it, unless something was screwy with the meter. The batteries are good and it's a fairly new electrode, so it's sort of puzzling.

Anyway, I'm going to see if I can borrow a neighbors pH meter and see if his gives me similar results. I have calcium carbonate, but I don't want to start adding it if by some chance the pH reading is wrong.

Thanks again!