Hi guys - thanks for your advice. John - I have not tested to see if MLF has completed - had a hard time getting Chromatography paper around here. Need to order on-line. I racked the larger vessel last night and tested the PH. PH is currently 3.0. Would you recommend I just assume MLF is complete now that it has been 3 months and look to adjust the PH by moving to adding Potassium Bicarbonate and cold stabilize for a while? Greg-
Are you certain of that pH reading, what method did you use to test it? If 3.0 is the correct pH, I doubt seriously that MLF is complete, it probably didn't even get started with a pH that low.
At any rate, you sort of have things out of order here, best practices are to adjust your pH and TA prior to alcoholic fermentation, attempting to achieve a pH in the 3.5 - 3.6 range, with a TA around .6 - .7. These ranges facilitate a clean AF as well as MLF, and a wine that is microbiallly stable.
Cold stabilization of a wine with a pH under 3.6 will decrease the pH, not raise it, so if 3.0 is the right number, don't cold stabilize.
In your current situation, these are the steps I would take:
1. Get all of the Marquette racked into a vessel(s) with proper head space
2. Confirm that the pH reading is correct, using a good meter that is properly calibrated.
3. If it's not 3.0, but something higher, like 3.5ish, run a chromatography to see if MLF is complete, and get it sulfited if it is, give it a bit longer if it is not.
4. If it really is 3.0, I've attached an article below that will help you with your acid adjustments: