The air temperature in your kegerator or lagering fridge doesn’t always track with the temperature of your beer, so a thermostat that’s measuring air temperature isn’t controlling the right thing. To get a consistent temperature you need to measure the temperature of the liquid.
I tend to be more of a “relax, don’t worry” kind of a brewer. My process makes very good beer, and that’s good enough for me. But that means that one batch of my California Common is not always the same as the next batch. They’re both good, but they’re not consistent. I’m okay with that — at least for now — but if I wanted to fix it, one of the main ways to get more consistency with your beer is to control your temperature better, especially during fermentation.
Recently I heard about the Sure Temp Thermometer and I was curious about it. I asked Chris at Maryland Homebrew about this and she said “we have been telling customers to do just this with empty white labs vials. They drill a hole in the lid and stick their thermostat controller into it.”
There’s the DIY solution if you love to tinker, or if you want to buy one pre-made, go here, or read more about it on this page — Sure Temp Thermometer Measures Product Temperature.
If you want to learn more about the importance of temperature control, here’s a good page. Fermentation Temperature Control. It says “Fermentation temperature control is the single most important thing you can do that will make the most dramatic improvements in your beer.”
Okay, maybe. Don’t people say that about sanitation?