What is Reddit's opinion of Kombucha Heater | Fermentaholics Kombucha Brewing and Fermentation Heat Mat | Keep your SCOBY Happy and Productive By Brewing In The Proper Temperature Range?

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You don’t have to wait. Just use some kind of kombucha heating wrap like this https://www.amazon.com/dp/B07F1B2HMB/ref=cm_sw_r_cp_api_glt_i_DB4AM1PKAG2MY83G9RNK

I use a heating mat for 1F: I found that my batches majorly improved in both flavor and consistency after buying one. Some US-centric examples: a basic mat I see recommended is this one (https://smile.amazon.com//dp/B07F1B2HMB, $16, no temp control) and the one I personally use is this one (https://www.happyherbalist.com/kombucha-heating-pad-thermostat/, $55, temp control).

For 2F, cold temperature 2F is very possible! I’ve found that 2F length depends hugely on temperature. I live in an older building in a mild climate in the US with no AC and minimal insulation, and see that my 2Fs take 7-8 days at 50-60F/10-15C in the winter that shortens to 18hrs at 90-95F/32-33C during the occasional summer heat wave.

If you’re having poor carbonation after waiting 10+ days at 17-18C then something else could be going on (sugar/headspace/bottles/not stirring after 1F/etc): I’d recommend comparing your process to the wiki - https://www.reddit.com/r/kombucha/wiki/carbonation/. Some people on this sub use heating mats for 2F to raise the temperature, so that is another possible route if low temperature ends up being the culprit.

Heat mat This is the one that i’ve been using for a while, but i’m sure any similar ones should work good as well!

I have been using this one for a few months:
https://www.amazon.com/Kombucha-Brewing-Fermentation-Heat-Wrap/dp/B07F1B2HMB/
After three years of making kefir, mine started behaving quite differently this fall, after I switched to ultra-pasteurized milk. Wrapping this around the jar is one of the ways I have managed that as the cooler temps in the house slowed the fermentation.

I'd guess that it's meant to block light. Kombucha fermentation produces effectively no heat, so adding a wrap won't help much to warm it up. A wrap could have some insulative effect against external temperature swings, but without being able to add heat a wrap won't help keep a brew much warmer than ambient temperature.

Consider a heating mat like this one: https://smile.amazon.com//dp/B07F1B2HMB ($16, no temp control) or the one I personally use https://www.happyherbalist.com/kombucha-heating-pad-thermostat/ ($55, temp control).

I use a heating mat for 1F: I found that my batches majorly improved in both flavor and consistency after buying one. A basic mat I see recommended is this one (https://smile.amazon.com//dp/B07F1B2HMB, $16, no temp control) and the one I personally use is this one (https://www.happyherbalist.com/kombucha-heating-pad-thermostat/, $55, temp control).

Echoing the other comments suggesting a heating mat. I found that my batches majorly improved in both flavor and consistency after buying one.

Some US-centric examples: a basic mat I see recommended is this one (https://smile.amazon.com//dp/B07F1B2HMB, $16, no temp control) and the one I personally use is this one (https://www.happyherbalist.com/kombucha-heating-pad-thermostat/, $55, temp control).

70-72F is reasonably cold for 1F - ideal is 80F. Colder temperatures slow down the fermentation, so a 20 day 1F isn't unreasonable to reach the taste profile that you like.

For 2F, 5 days seems reasonable at those temperatures - my 2Fs take 5-7 days at 55-65F, so yours are a bit slower but nothing too crazy.

Overall, I wouldn't be worried if you're not seeing mold and the kombucha tastes good to you! Maybe consider buying a heating mat if you want to speed up the fermentation. A basic mat I see recommended is this one (https://smile.amazon.com//dp/B07F1B2HMB, $16, no temp control) and the one I personally use is this one (https://www.happyherbalist.com/kombucha-heating-pad-thermostat/, $55, temp control).

Ones I've previously recommended:

https://smile.amazon.com/dp/B07F1B2HMB/ (mat only, $16)

https://smile.amazon.com/dp/B081YZ9RN2/ (mat + temperature controller, $30)

https://www.happyherbalist.com/kombucha-heating-pad-thermostat/ (mat + temperature controller that I've used for 2 years, $55)

Thanks for the details! Totally makes sense that you previously brewed beer. Think of kombucha as beer's less precise cousin :)

First thing I'd recommend is reading through the wiki if you haven't already - gives a great overview of the recipe + method: https://www.reddit.com/r/kombucha/wiki/how_to_start

I see a few potential problems with your setup:

• Not enough starter. I always recommend that people start off with 2x starter for their first few batches - really helps drop the initial pH to prevent mold (needs to be <4.5) and get the culture off to a strong start. For a first batch with 1 16oz bottle of GTs, a gallon is the max recommended batch size (1 part starter to 7 parts tea) with my ideal being 1/2 gallon (1 part starter to 3 parts tea). After the first 2 batches, drop down to the standard amount of starter from the master wiki recipe.
• Not enough tea. The master recipe uses 3 bags per quart, or 12 bags per gallon. English breakfast tea is a perfect variety to use - it's strong unflavored black tea.
• Temperature too cold. Ideal brewing temp is 76-80F and fermentation significantly slows below 65-68F. As a new brewer, it will be difficult to have a successful batch at those temperatures and the brew will be more prone to mold (pH isn't dropping as fast as a warmer brew). I'd recommend either finding a warmer spot in your home or buying a heating mat - they're $15-35 and really help. Examples: https://smile.amazon.com/dp/B07F1B2HMB/ (mat only), https://smile.amazon.com/dp/B081YZ9RN2/ (mat + temperature controller), https://www.happyherbalist.com/kombucha-heating-pad-thermostat/ (mat + temperature controller that I've used for 2 years)
• Using an airlock. As you realized, the bacteria in the kombucha culture require oxygen to be active, so using an airlock causes the bacteria to go dormant. The lack of bubbles you saw was probably caused by lack of yeast (from the weak starter transferred from batch one to batch two). For your next batch, go back to using a coffee filter or tightly woven cloth (quilting fabric, old tshirt, basically anything but cheesecloth).

Other note - StarSan is okay to use, but is not normally necessary for kombucha. Kombucha's low pH inhibits mold and other bad stuff from growing, so kombucha brewing gets away with being much less sanitized than beer. Washing your vessel (and other equipment) with dish soap + hot water between batches is generally enough to stay clean. It's totally fine to keep using StarSan if you want too though!

Hope this helps - good luck!

I imagine it depends partially where you are. I've started my first batch last week (Christmas is great!) and it's been hovering around 68 F, because the apartment has old heating and I live in Canada. If you live in a cold area like I do, and you expect it to get colder, then it might be worth preparing. I'm getting a heating pad from Amazon - I don't know yet how well it'll work, but we'll see! https://www.amazon.ca/gp/product/B07F1B2HMB/ref=ppx_yo_dt_b_asin_title_o00_s00?ie=UTF8&amp;psc=1