With winter and cooler temperatures upon us, it’s time to discuss the effects colder weather has on fermentation. The cooler temperatures mean more problematic experiences with stuck fermentations and/or extended clearing periods.
Yeast is very temperature sensitive. For every degree below 70 add a day to the fermentation time. For every day below 64 add two days and every day below 60 will add a week. To wine and beer makers who count days rather than using the hydrometer, this spells b-a-d news. A delay of a few days may result in brewers bottling before fermentation is complete and wine makers stabilizing too early, clearing problems and re-fermentation in the bottle.
Super-Kleer KC, isinglass and the fining agents included in Winexpert kits are equally sensitive to temperature. They simply won’t work in colder environments. Clearing rates will be affected in the same way as yeast when the temperature drops. So it is important to allow fining the proper amount of time at a stable room temperature to function properly. This is especially important for those who use cold stabilization to hasten tartrate drop out in the carboy. Be sure cold stabilization is begun only after the finings have been given their chance to work in a warm environment.