Brewing kombucha at the ‘wrong’ temperature creates problems, both when too hot or too cold.
TOO COLD: (under 20C / 68F)
This is the issue that I troubleshoot the most, especially in the winter months.
MOLD! – The biggest issue with brewing kombucha at temperatures under 20 Celsius / 68 Fahrenheit is that it puts your brew at risk for mold. Kombucha bacteria are less active and produce essential acids more slowly. These acids are the major reason kombucha is food-safe at room temperature and prevent mold.
SLOWER BREW TIMES – Brewing at low temperatures (< 23C / 73F) dramatically slows your brew time. Instead of a 7-10 day cycle, it can take as long as 4 weeks to reach the sour/sweet taste you prefer.
SLOWER SCOBY GROWTH – The scoby pellicule cellulose is there to protect your brew from outside bacteria, yeast, mold, and other contaminates. It is important for a good thick healthy scoby to form as quickly as possible.
MILDER TASTE – Neither a good or bad thing but generally kombucha brewed at lower temperatures will be milder in taste.
TOO HOT: (over 27C / 80F)
There is no doubt that temperatures near boiling will kill your kombucha culture, hence why it is so important to cool your sweet tea before adding the culture.
YEASTY – At higher temperatures, the yeast is more active than the bacteria and this can lead to an unbalanced brew. Having lots of yeast is great for carbonation but the bacteria can get choked out. The probiotic bacteria are important as they create healthy components like detoxifying organic acids and vitamins.
FASTER BREW TIME – When kombucha brews very quickly, it doesn’t leave time for the bacteria to produce as many beneficial organic acids and vitamins.
SHARP ACIDIC TASTE – The faster brew time gives your kombucha a sharp acidic taste.
I recommend brewing at 23-24C / 73-75F. I prefer the flavour created at this temperature and allow both the yeast and bacteria to contribute to a fizzy healthy kombucha.
So how do you ensure you are brewing at 23C / 73F?
By using the built-in thermometer on your Karma Cultures Kit you can easily monitor the current temperature of your kombucha at a glance. The goal is to increase the ambient temperature. around your vessel.
- Option 1. Turn up your household thermostat.
- Option 2. Find a warmer spot or room in your house and brew there.
- Option 3. Create a nest or den for your brew. A picnic cooler or a thermal bag will work. Tuck in a towel with a hot water bottle to keep your brew warm for a few hours. Make sure to keep the top of the brew open for airflow.
- Option 4. ‘Set it and Forget It’ – Invest in a heat strip and thermostat. This allows you to brew anywhere in your home and control the brew’s temperature super easily. Buy them here Heat Strip Thermostat
Remember to keep it warm!