We brought our science project inside. The nights have cooled considerably, dropping into the 40s. The energy of fermentation defies the weather to some extent; our grape juice has held around the mid 60 degree mark.

The goal is for the sugar levels to drop to slightly below zero (from their original highs of almost 30). If this fails to occur, fermentation “sticks”, and will require the addition of a new strain of yeast to kick-start, then finish off, fermentation.

We’re in the home stretch – around 5 brix. But 3 factors worry us:

(1) The BM45 Brunello yeast we added to the grapes to attack the sugars operates at 64 degrees or above – fermentation subsides otherwise. We’re riding the line, it seems, keeping the bins outdoors.
(2) Our nightly monitoring of brix levels indicates sluggishness in the sugars’ march toward elimination. Last night, we recorded just 1.5 degrees of change, half as much as the prior readings.

(3) Another kink: we plan to press in 3 days. This corresponds to Anthony’s day off and my last day before a business trip. But we can’t press with sugars still present.

We decided to bring the bins into the living room to provide warmer, predictable shelter. The cats certainly found this intriguing, sniffing where the lids snap on, and discovering new cliffs for pouncing.

To rally the fermentation further, we employed a trick. We bought an aquarium lamp to submerge, bin by bin, in the juice. As we prep dinner or watch a movie, we’ll pause to shift the lamp’s position within and between the bins, using barbecue tongs. Healthier bubbling already suggests the effort might pay off.