Kombucha brewing in the 8 litre glass jar: a cloth draped over the top, a metal tap at the bottom, the jar on a wooden stand.
fermented
soda lab

fizzy kombucha, every time.

One 500 ml bottle plus 3.5 grams of sugar (about ¾ of a teaspoon of white sugar) plus a cap makes 2.5 volumes of CO2, as fizzy as a lager.

A starting dose for kombucha after F1. Check a tester; fridge the bottles when it's firm.

get the kombucha cheat sheet PDF

1 page · ~400 KB · no email needed

how fizzy
is fizzy?

Brewers measure fizz in volumes of CO2: litres of gas dissolved in each litre of drink. Pick the number first, then dose the sugar for it. Each cell below is half a volume.

  1. cask ale 1–1.5 vol gentle
  2. lager 2.5–3 vol lively. start here
  3. cola 3.5–4 vol soda-sharp
  4. wheat beer 3.5–4.5 vol big and foamy
  5. champagne 5–6 vol not in normal bottles

Typical values, rounded. Solid cells mark the low end of each range, outlined cells the rest of it.

no gauge? squeeze a tester.

  1. 1Fill one plastic soda bottle from the same batch.
  2. 2Squeeze it once a day.
  3. 3Hard to squeeze? Every bottle goes in the fridge.

Cold stops the build-up and locks the fizz in.

start with a kitchen scale.

You don't need a lab. Every recipe here works at level 0, with the numbers for anyone who has more.

  1. Level 0: Kitchen scale, your tongue, one squeeze bottle

    Consistent sugar doses, and knowing when F2 (the bottle stage) is done.

    you own it

  2. Level 1: pH strips and a thermometer

    A safety check before bottling, and why warm batches run fast.

    ~€10

  3. Level 2: pH meter and refractometer

    Exact sourness and sugar. Recipes you can repeat.

    ~€20–40 each

  4. Level 3: Gauge cap

    Fizz as a number, and the fun experiments.

    ~€15–25

check before you bottle.

Close up of the 8 litre kombucha jar in natural colour: amber kombucha, a hand-written tape label and the metal tap.

five years into brewing, a few months into kombucha.

I'm a German homebrewer and International Beer Sommelier, Deutsche Bier Akademie (DBA). Ginger bug, water kefir and tepache I'm learning from zero, in public. Every batch gets logged, failures included.

exp
#001
day
–
temp
– °C
pH
–
fizz
– vol
status
not started

EXP #001 hasn't started yet. Its numbers land here as they're measured: outlined while they're pilot data, solid once confirmed.

watch the experiments@fermentedsodalab

the full sugar table is free.

get the kombucha cheat sheet PDF

1 page · ~400 KB · no email needed

Or comment FIZZ on any post and it lands in your DMs.