In my quest to control temperature to get the best results from my sourdough I assembled a very effective proofing box made from a couple of plastic tubs and an old fish tank heater. I use it to active the culture, bulk fermentation and the final fermentation (when not retarding in the refridgerator).

Just put the heater in the bottom of one tub, part fill with water; just enough for the second tub to sit snuggly inside and float making contact with the water and put the lid on. Easy and cheap. After a bit of testing and altering the dial, I have a constant 24 C. I can increase or lower the temperature as required (although I find I get great results by leaving it at around 24 C for every phase).

The pictures are attached here and also a liquid levain (125% hydration) after being in the proof box overnight.

I discovered the idea on the internet about 12 months ago.

Cheers,

Gavin.

active liquid levain out of proofing boxproofing box 2proofing box