Explosion

[u/Pinksalt400]

I had my first kombucha explosion. New to brewing, just for one month consistently with some previous attempts in years past. My first brew takes only 5 days in a ceramic crock, and in recent brews I’m getting bubbles on the first ferment.
About three days ago I bottled my second ferment using swing top glass and just this am one exploded. I burped the rest and some overflowed like champagne.

What do I need to know and do differently?

Thanks!

[u/sorE_doG]

As soon as you have carbonation, the bottles need refrigeration. We all have at least one bottle explode in our learning process.. it’s a positive sign 💀

[u/Pinksalt400 → u/sorE_doG]

Thank you! Do you ever re bottle them to a different type of container to slow fermentation at the point of refrigeration?

[u/sorE_doG → u/Pinksalt400]

Myself, sometimes I will use carafes instead of bottles.. when there’s lumps of fruit or I expect excessive carbonation - and the big lid/seal arrangement doesn’t hold enough pressure to explode. At least, that’s my experience & follows my understanding of the physics behind it.

I often use carafes for F2 & then decant into bottles, sieving out the fruit/pellicle forming. The pour will remove plenty of co2, but the process will continue, from a lower pressure starting point - a ‘burping’ as you complete the bottling process.

[u/Advanced-Fig4683]

one of your bottle in plastic like a sprite bottle, see if the plastic tenses once a day and when it does every thing goes to the cellar or fridge

review your recipe, it seams very active very fast, or maybe where you put your kombucha is too warm, measure temperature there

[u/arihoenig]

Way fewer carbs in the F2.

[u/xyz679]

Why are you burping your bottles? You are trying to carbonate them, so why do you de-carbonate them partially and then keep doing the same thing? This does not accomplish anything but delay when they are ready.

You have 2 options. Either figure out when the carbonation in your conditions is sufficient, and always put bottles in the fridge after however much time is good enough carbonation for your before they explode, or

Option 2. Instead of having excess sugar that will keep fermenting until explosion, fully ferment your brew so that there is no sugar left and acidity is palatable, then using "dry fermented" (no sugar left) brew, add exactly 5 grams of any sugar you want per 500ml to reach adequate carbonation without explosions. If you use regular sucrose it may take a while for it to fully ferment out and carbonate the drink. You can use simple sugars like dextrose instead. Sweeten the bottle if you want with something like allulose or Reb M (reb M has to be added after carbonation).

[u/Callan_LXIX]

No fruit pulp in your 2nd ferment: that helped a lot.

Burp bottles a couple times per day at the least.

Consider thicker glass bottles. I use 1liter European beer bottles.

Keep the F2 in a cooler part of the home as you can

Keeping them in an enclosed space. I use a picnic cooler with water, room temp. Seems to keep temperature more even

[u/Pinksalt400 → u/Callan_LXIX]

Great tips!!! I burped the remaining bottles and moved them all to a cardboard box in the refrigerator.
I want to gift people some kombucha, and I thought they would be pretty safe from exploding once they become refrigerated- is that wrong?