I just started fermenting my 4 buckets of Chilean juice yesterday, and I measured the PH and TA but didn't add any acid even though the levels where a little low because the PH seemed pretty low too. All the buckets had started fermenting at least a little bit already, and I didn't heat the samples to drive of co2 before testing, but here are the numbers I measured.
Cabernet Sauvignon: OG: 1.093, PH 3.2, TA: .50%
Malbec: OG: 1.090, PH 3.3, TA: .51%
Carmenere: OG: 1.084, PH: 3.2, TA: .47%
Sauvignon Blanc: OG: 1.100, PH: 3.2, TA: .42%
I'm wondering if I should add acid blend to these wines? If so should I add it now or wait till after fermentation finishes, and should I just follow the recommended levels for the TA or try to adjust it to taste? I also have the individual acids (except for lactic acid) if that would be better than the blend. I'm also planning to do a malolactic fermentation on the red wines, which I read has trouble below a ph of 3.2.
Just to make sure I did the calculations right, the titration for the Malbec used 5.1 ml of .2N NaOH to change the PH to 8.2.