I recently made wine from frozen must from Peter Brehm, two pails which makes about 5 gal after the first racking. Before pitching the yeast I let the must warm up to room temperature, measured acid: 4.65 g/l, ph: 3.46 and brix:24.6. I decided to bring the acid up to 6 g/l by adding 266g of tartaric acid. I didn't remeasure before starting fermentation. After I pressed the wine I remeasured it, acid: 5.4g/l, ph: 4.7!! Can anyone explain what may happened here? I was concerned with the ph going too low after I added acid but the opposite happened? I have never measured ph so high? I calibrate my ph meter before using every time. It measures my calibration solutions perfectly, so I don't think the measurement is incorrect. 1. Can anyone explained what may have happened? 2. What can/should I do now?