It’s hard to believe, but the UK is predicted to actually have HOT temps this week! I am loving that, but unfortunately, your small-batch fermenting beer will not. Because we brew in small batches, there is less volume to moderate temperature changes, so we need to be careful to protect Fermo and your fermenting beer inside. Luckily there are a few steps you can take to ensure a great result.
1. Make sure Fermo is out of direct sunlight – actually on these hot days, as much in the dark as possible would help.
2. Heat rises right? So keep Fermo as low to the ground as possible so you are doing all you can to keep the temp down. On the ground, or solid flooring is probably best on these hot days.
3. Evaporation cools – wrap a wet tea-towel around Fermo – a wet tea-towel in a cool box works even better! Just be sure to keep the airlock clear.
The aim is to keep Fermo at 22 degrees or lower if possible. What will happen if your fermenting beer gets too hot? The yeast will become over-active and produce too many by-products which add banana-esters and other off-flavours to your beer. It will probably still be drink-able, but will have flavours that are not meant to be in it!
So again, best set-up would be a cool-box on the ground out of the light with an ice cube or two (not too many) and a wet tea-towel wrapped around it to keep your beer between 16-22 C.