TEMPERATURE
​Whether fermenting food or drink, sanitation is the primary precaution, but temperature is also a critical concern.​​​
  • Colder temperatures will lengthen fermentation time, while warmer will shorten it.​​
  • The SCOBY is tolerant of a relatively wide range, but too cold (below 64 degrees Farenheit) could cause mold, and too hot (above 95 degrees) will kill the B part of the SCOBY. The Goldilocks happy medium is a just right 80 degrees. ​
  • If taking a break between batches, do not refrigerate the SCOBY.
  • Only refrigerate kombucha that is ready to drink.
 Room temperature is more likely to be within the optimum brewing range during the summer months, but the rest of the year the challenge is to warm the primary fermenter without having to heat the whole house.
​   The best solution for temperature control is a heating mat, which wraps around the fermenter and is secured with a velcro strap. The dimmer can be adjusted so that the liquid in the gallon glass jar is continuously warmed to the ideal 80 degree temperature.
   A much cheaper but less controllable solution for keeping the primary fermenter warmer than your house thermostat setting is an easy-to-make gallon jar cozy. Don't expect it, though, to warm the liquid more than a few degrees higher than the room temperature.
   Rummage the recesses of your closet or the racks of the local thrift store for a men’s large wool sweater, cut off one of the sleeves, and for a warm and snug fit, stretch it over the gallon jar fermenter.
Yoda Ugly Sweater
Warm You Must Keep Kombucha
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​If you have floor air vents you can help even more to keep the primary fermenter warm in the winter and cool in the summer by placing the gallon jar on the bottom metal grate shelf of an end table. Positioning the jar directly over the vent will allow air to flow underneath, and the solid table top will keep air circulating around the upper part of the fermenter.