As a kombucha home brewer I want to make sure to treat my kombucha and its living bacteria culture right, so that my booch turns out as tasty and healthy as possible. One important part of that is making sure that my kombucha is brewed at the right temperature.
So what is the right temperature for brewing kombucha?
Kombucha can be brewed at a temperature of anywhere between 65-85 degrees F (18-29 C). However, the ideal kombucha brewing temperature is 75-78 degrees F (24-26 C). Too cold of temperatures will slow down the bacteria culture that ferments kombucha, leading to a longer fermentation time and greater vulnerability to mold growth, while too hot of temperatures will cause extra yeast growth that can lead to a bad taste and lowered amount of probiotics.
In this article I’ll cover everything you need to know about kombucha and temperature to confidently brew the best kombucha possible without ever ruining a brew again.
Why Kombucha Brewing Temperature Matters
Brewing Kombucha at Cold Temperatures
When kombucha is brewed at colder temperatures, the living bacteria culture that ferments it becomes less active. And a slower bacteria culture means that fermentation will take longer.
For example when I brew kombucha during the summer my 1st fermentation, brewed around 75 degrees F, usually takes around 7-10 days. But when I brew kombucha in the winter, at a temperature of around 65 degrees F, the 1st fermentation can take 3-4 weeks.
Kombucha brewed at colder temperatures also has a milder, weaker, and sweeter taste since the lethargic bacteria are processing the sugar into alcohol and acids much slower.
The biggest problem with brewing kombucha at cold temperatures is that a less active bacteria culture is not producing many acids. It’s these acids and the highly acidic environment of kombucha that prevent mold growth. So if the kombucha is being brewed at too cold of temperatures, it will be less acidic and more vulnerable to being contaminated and ruined by mold.
Brewing Kombucha at Hot Temperatures
When kombucha is brewed at hotter temperatures, its bacteria are more active, and ferment the brew faster.
If the brew is too hot (above 85 F, 29 C) it will become extra yeasty because yeast love warm temperatures. Too much yeast will choke out the beneficial bacteria that give kombucha so many of its health benefits, and make the brew taste really bad.
So at what temperature should kombucha be brewed at? Well kombucha can be brewed at a temperature of anywhere between 65-85 degrees F (18-29 C). However, the ideal kombucha brewing temperature is 75-78 degrees F (24-26 C).
How to Find the Temperature of your Kombucha
The easiest way to check if your kombucha is brewing inside of the correct temperature range is to just check your household thermostat.
This will tell you the temperature inside your house, which obviously won’t be the exact temperature of your brewing kombucha, but it will give you a ballpark idea that will help you keep your booch brewing within the 65-85 degrees F (18-29 C) range.
To get a more specific reading of the temperature of your kombucha you can use a thermometer. Just stick it a few inches down into your brewing booch as often as you’d like and you’ll know the exact temperature of it.
My favorite method for keeping track of the temperature of my kombucha is a temperature strip. A temperature strip is like a thermometer, but it sticks onto the outside of the brewing vessel and will light up to tell you the temperature of the room that you're brewing in.
Plus It doesn't require any electricity sine it lights up in a similar way to a mood ring.
The great thing about temperature strips is that they’re easy. To get the temperature of your brew you just look at it. No opening up the vessel, moving around the SCOBY, or messing with any liquid.
How to Keep your Kombucha Warm
If you check the temperature of your brew with one of the methods mentioned above and find that it is too cold, there are ways to warm it up.
If your kombucha is only a few degrees too cold, you can either move it into a warmer area of your house or turn up the thermostat a few degrees.
However if you need to warm up your kombucha significantly, the best and easiest way is to use a kombucha heating pad. A heating pad wraps around your brewing vessel and can warm your kombucha up 10-15 degrees F (5- 8 C).
Some even have thermostats so all you have to do is set it and forget it and it will adjust by itself to keep the kombucha at the right temp. Others have multiple heat settings so you’ll have to keep track of the temperature and adjust it yourself.
Kombucha heating pads are made to keep your kombucha warm 24/7 so they are super energy efficient and run on very little electricity, which means you won’t have to worry about them running up your electricity bill.
Where to Get a Kombucha Heating Pad
My favorite wrap around heating pad is Perfect Kombucha’s Fermentation Heater. This kit allows you to control the temperature of your kombucha with 4 separate heat settings, and allows you to monitor the temperature accurately with the included temperature strip.
Perfect Kombucha has so much confidence in the quality of their heating pad that they guarantee you a 100% refund within one year of purchase if you’re not satisfied. If you’re interested, you can find their wrap-around heating pad on Amazon here.
If you’re on a budget but still need to heat your kombucha, you can get VIVOSUN’S Wrap Around Heating Pad for only $10 and with free shipping on Amazon here.
Other Ways to Heat Up Your Kombucha
A few other things you can do to heat your kombucha are:
Store the kombucha above the refrigerator or on a high shelf where the air temperature is usually warmer.
Wrap the kombucha with a towel for insulation.
Place the kombucha, on top of a plate, on an appliance that's always running like a DVR.
Some people recommend wrapping your brewing vessel in Christmas lights, placing it in the oven with just the light on, or putting it near a lamp to keep it warm. However, I wouldn’t recommend doing these things since some studies have found light to be antibacterial. Meaning that exposing your booch to light for extended periods of time could damage the bacteria culture.
Whether or not this is the case, brewing pads are so cheap and there are so many other ways to heat your kombucha that I would play it safe and avoid using lights to heat your booch.
How to Cool Down your Kombucha
It’s pretty unlikely you’ll ever need to cool down your kombucha brew, since this would only be needed if the temperature of the booch was above 85 degrees F (29 C), and it's extremely rare for someones house to be this hot.
But if by chance you’re A/C goes out during the summer and you need to cool down your kombucha, the easiest thing to do is place it somewhere cool and dark like a cupboard or in your basement.
If your brew is really hot, it’s okay to place it in the fridge for a little bit. Just be sure to take it out once it has cooled down to a temperature inside of the brewing range (65-85 F, 18-29 C).
Do not ever put your brewing kombucha in the freezer, since the extreme cold can shock the bacteria culture.
Kombucha Temperature for 2nd Fermentation
So far, all I’ve been talking about is keeping your kombucha at the right temperature during 1st fermentation, but what about the 2nd? When the kombucha is carbonating and flavoring.
The temperature of your kombucha during 2nd fermentation isn’t as important as during 1st because it's unlikely for mold to develop at this stage. However, too cold a temperature during 2nd fermentation could mean your booch takes a long time to develop carbonation, or doesn't develop carbonation at all.
If your bottles during 2nd fermentation are too cold, you can warm them up with the same methods that we talked about earlier. The easiest being wrapping them in the kombucha heating pad.
Keeping your kombucha in the temperature range of 65-85 degrees F (18-29 C) is important for the brew to turn out tasting good, without mold, and on time. This really should not be difficult since almost all homes are kept at a temperature somewhere within this range, but a heating pad may be necessary in the wintertime.
If you want to learn more about keeping your kombucha at the right temperature, check out this helpful video by YouBrewKombucha: https://youtu.be/uVwOfs8kTTg
And if you want to learn more about kombucha, how it relates to your health, and even how to brew it yourself, be sure to check out the rest of my website!