I use brew belts almost religiously.
Problem with them is they don't really regulate, they just keep pouring on the heat all the time. I achieve some regulation by sliding the belt up and down the bucket or carboy. The lower it is on the bucket, the warmer the wine will get.
I have a Canadian friend who came up with the idea of using fish aquarium heaters. He places his fermentor bucket/carboy in a tube, which is just a few inches greater in diameter than the bucket. He fills the cavity between the tube and bucket with water. He floats two of the long-bodied aquarium heaters (longer the better) in the tube, between the walls of the tube and the fermentor. One can put a jacket of some kind around the tube and bucket to better transfer the heat from the water into the fermentor.
These aquarium heaters' temperature is adjustable and fairly well regulated.
For me, since I have a very cold basement in the winter, This would work great for fermenting a nice white wine, which needs its fermentation temperature kept in the low 60's F.
Also good for fermenting reds. When I pitch the yeast, I add the brew belt to keep the temp up. Once fermentation starts, I typically remove the belt, because the fermentation generates enough heat on its own. If I used the aquarium heaters, once fermentation starts, they would just shut off on their own. Once fermentation slows, the heaters will kick in again.
Thanks RR.
