Set it on top of the warm hood. It heats when you need it and cools when you don't. You can add the bottle to a heated bucket of water or use a reptile mat etc. Regards, Tom Barr > My question is how to keep the yeast warm enough at night so it doesn't take > 1/2 a day to start producing CO2 again? My house drops to about 60 degrees > at night during the winter (we have wood heat). > > Terry