Sluggish Fermentation Woes
Charles Rizzo — Bensenville, Illinois asks,
Last spring I purchased some Sauvignon Blanc juice made from Chilean grapes (Brix was 24.5, pH was 2.95, TA was 0.45, and the temperature at the time of receipt was 40 °F/4 °C). The product seemed to be in fine condition; no swelling of pails from fermentation, good smell, color etc. I allowed the juice to warm overnight to 60 °F (16 °C) and inoculated with QA23 yeast following the recommended technique of hydrating and feeding with Go-Ferm and began fermentation. Four months later, the wine was at -0.01 °Brix (still fermenting). I added Fermaid K at the recommended level and time. I even bumped the temperature to 75 °F (24 °C). Why did the fermentation take so long? I believe the grower/processor did something to retard fermentation during shipping. What would they have done? The numbers seem strange also, I usually work with fresh fruit and normally see the pH around 4 to produce a TA of 0.45 (at pH 2.95 I expected TA 0.7+). This wine doesn’t fit my past experience and I am looking for answers. I hope
you can help.