Low pH, should I adjust, if so, how

[oregondabbler]

Question: Sugar is a little low, wine will probably ferment to be dry, which is OK with me. The pH seems low. Should I try to adjust pH now or wait it out?

Details:

Chardonnay grapes were picked Sunday Oct 12 (3 days ago). Grapes were crushed, stemmed and pressed that day. About 30 gallons of juice. Added sulfite solution to give 50 ppm SO2.

Let sit, covered in the Brute barrel until this morning (Wednesday, Oct 15). Temperatures were between 55 and 64 F. Reason for letting sit so long: I planned on using a starter which wasn't ready until this morning. Before pitching yeast, I stirred the barrel and pulled my sample for analysis.

Results:
s.g.: 1.090
Brix (refractometer): 20%
TA: 0.78%
pH: 2.85

I pitched Red Star Cote Des Blancs after taking the sample. Fermentation temperature is whatever is ambient in my barn, at this time about 63 F.

 

[Turock]

Well, the PH is definitely on the low side. How does it taste to you ? It's best to try to adjust before you start the ferment. A small dose of calcium carbonate would bring up the PH. If you intended an MLF on this wine, it will be impossible now with that low a PH. You might also look into a product called acidex--after the ferment, you may want to bring the PH up. Taste it as you go and stop when you like the flavor and acid.

 

[oregondabbler]

Thanks Turock,

I wasn't planning on MLF but I guess that decision was made for me. The juice tastes great, more tasting is in my future it seems!

What I read about Acidex is that it is not to be used on wine, only use on juice before fermentation.

Lesson learned about checking the wine well before pitching the yeast. I'll wait it out and see what happens.

 

[Turock]

Yes--you have to understand that it's at the PRIMARY where you design the wine. It's best if you make all adjustments pre-ferment as they integrate better and make a balanced result.

If the juice didn't taste too acidic to you, then that PH might be just fine. It will rise slightly anyway during the ferment. Fruit-forward Chard is very good!! I like it that way OR MLF'd so no big deal.

 

[ibglowin]

It will be nice and "crisp" for sure with that pH. Hopefully the pH will rise a little post fermentation.

 

[PCharles]

I made a cranberry wine that had a low pH like yours. I had a heck of a time getting it to start fermenting. I added carbonate to bring up the pH. It finally kicked in and ended up fine.

 

[oregondabbler]

I made a cranberry wine that had a low pH like yours. I had a heck of a time getting it to start fermenting. I added carbonate to bring up the pH. It finally kicked in and ended up fine.

Thanks for the reply. What pH did you bring your batch up to?

I did not adjust pH in my must. Due to previous experience with grapes from these vines, I expected fermentation would be hard to get going. So, for this batch, I pitched a half-gallon of starter made from packaged concentrated grape juice (white wine grapes diluted to ~20% brix). The starter took its time to get going but fermentation took off a day after it was pitched into the must.

This morning, seven days in, the fizzy juice tastes great but is still sweet.

Fermentation has been slow but consistent. Temperature is between 61 and 65F, yeast is Red Star Cote des Blancs. Seven days into fermentation, specific gravity, which started at 1.090, is now 1.028 and I pick up some H2S when sniffing the air above the barrel. I added yeast nutrient (1/4 tsp DAP/gal dissolved in 1 cup water), stirred and splashed. Am thinking of waiting until SG gets below 1.010 before racking to carboys.

I will be grateful for any comments or suggestions.

 

[deRicardo]

I have not used Red Star Cote des Blancs, so I can't say, but some yeasts produce fermentation smell that is really intense, but not necessarily H2S. Even though this is a white, if you still suspect H2S, open the fermenter and stir it once every other day until fermentation ends. That won't really hurt the white.

Since you have now added nutrient and hopefully will keep its level where it should be, don't worry about that smell until fermentation is completed.

If after fermentation is done you still have the rotten egg smell, deal with the possible H2S problem.

 

[oregondabbler]

Thanks, deRicardo,

Its been one day since the last reading and nutrient addition. Maybe I'm being obsessive. I checked this morning and the smell is gone, the SG is now at 1.018, with lots of fizz in the barrel. So, all's well. Again, perhaps I'm being obsessive, but added some yeast energizer (1/8 tsp/gallon or 25% of the recommended amount). The pH of the must was low and I'm trying to help the yeast to get it to finish with a dry wine.

Question: What do you mean by "keeping its level where it should be"?

Since you have now added nutrient and hopefully will keep its level where it should be

Was there a schedule that I should have followed for adding nutrient?

Thanks again

 

[Boatboy24]

Was there a schedule that I should have followed for adding nutrient?

Thanks again

At about 1/3 sugar depletion.

 

[deRicardo]

Sounds like you are back on track with that nutrient addition.

Some like to add nutrients in several smaller doses, which I guess is OK, but I have never done it that way. If you added the proper amount of nutrients in one dose, the level should hold just fine until fermentation is done.

Just follow the directions that came with the nutrient.