So, my wine is at 6 brix now and the ice all melted so I took it out because I was afraid that some of the bags might start leaking. I was looking into dry ice and found this: http://www.barrelblasting.com/dry_ice_info_sheet.pdf
They say that 7.3 lbs of food-grade dry ice pellets lowers the temperature 1 ton of grapes by 1 degree.
So, if I wanted to lower the temp of 1000 lbs of grapes by 10 degrees, I would need 36.5 lbs of dry ice pellets…or, 7.3 lbs for each of my fermenters.
The question is: is it worth it, and would that slow fermentation significantly more than just the fact that there’s less sugar is already doing? I’m guessing not. Still, this is good to know for the future.