When I first started homebrewing, I, along with most homebrewers living in warmer climates, had issues dealing with keeping a good ferment temperature during the hot days of summer. Living in Riverside CA, where it can reach 115 degrees easily during July and August, this was a problem for me. Back then, I couldn’t afford to buy a digital temp controller and fridge/chest freezer to make things easy (now I have one, and it was the best gear investment I could’ve ever made). I had to get creative and figure out a way to at least semi-control my ferment, all while not spending my rent money in doing so.
So, how does a homebrewer with modest means defeat the bane to our existence, which is summer heat? There are many DIY methods these days that will work great for homebrewers in almost any climate, one just has to pay extra attention to their precious carboys, and try and control any big temperature swings. The method I used until l I had my ferment fridge was crude and primitive, but also effective for my needs. Here’s what you’ll need:
- 2 Bundt cake pans. Cheap, pressed sheet metal versions will work fine.
- A couple old t-shirts you’re not going to be worried about getting extra wear
Here’s the method I used. Again, there are more sophisticated means, but this is very cheap and works well. Take both Bundt cake pans and fill with water. Put these into your regular freezer overnight. Once they are frozen, take a t-shirt, wet it down and wring it out so it’s not dripping. Place the shirt over your carboy. Next remove your airlock and stopper and place one of the frozen Bundt cake pans onto the carboy. The hole in the pan should be big enough to fit the neck of the carboy through; otherwise you’ll need to widen this hole. Voila! You’re done. After a few hours, give or take, the ice in the Bundt cake pan will begin to melt. This condensation will be absorbed by the t-shirt, which will start to wick the cold water downward. I would basically replace a pan in the morning before work, and again when I got home. Simply refill the pans with water and refreeze.
There are more elaborate methods, such as the long-time homebrewer favorite, The Son of Fermenter. Construction plans can be found here. As I mentioned, there are many ways to combat the heat and keep your yeast fermenting at proper temperatures. I hope this helps you as much as it did me when I was starting out. Cheers!