Summer is coming to an end, but the temperature outside is still ridiculous, right? As brewers, this presents several problems. Unless you’re willing to pay a dramatically increased AC bill, maintaining proper fermentation temperature can be difficult. Even a cool corner in the basement can reach temperatures higher than optimal for most ales and all lagers. If you’re a fan of Saison style beer, you’re all set, since those yeast strains thrive in warmer conditions. For most other beer styles though, small-scale temperature control is required.
One of the simplest and cheapest options, a swamp cooler, can help regulate fermentation temperature using ice and water. Find a bucket or tub large enough to hold your fermenter with room to spare. Fill the bucket with cold water and several frozen bottles of water. By increasing or decreasing the number of bottles, you should be able to reach a desirable temperature. Store several more bottles of water in the freezer and change them out morning and night.
A more hands off approach is to use an analog or digital temperature controller connected to a fridge or chest freezer. These devices regulate power to the fridge or freezer to maintain a preset temperature. While the initial expense is significantly more than a swamp cooler setup, the ease and consistency of the final result make the cost worthwhile. In addition to maintaining typical ale fermentation temperatures, temperature controllers can hold lagering temperatures in the 40-50 degree range, or higher temperatures necessary for farmhouse or wild fermentations.
Whether you decide to use a swamp cooler, a temperature controller, or something in between, remember that consistent temperature control during fermentation can improve your homebrew dramatically. High fermentation temperatures can produce excess fruity esters, which are undesirable in most beer styles. An ale fermented at 65-70 degrees will be noticeably cleaner than one fermented at 75-80 degrees. Do you have a temperature control method you prefer? Tell us about it on Facebook or via email. We love to learn new things!