A smooth cream or tan wet film
This is a new SCOBY layer forming: the pale cellulose mat many brewers call the SCOBY. It may start patchy, then join into a thin layer.
Normal, adjust or discard
Kombucha trouble?
Start with the evidence.
Appearance is useful, but not enough on its own. Combine what you see and smell with temperature, time and a recorded pH.
10 results
Brown strings or sediment
These are usually normal yeast strands from the SCOBY. They may hang from the pale layer or collect at the bottom of the jar.
The SCOBY layer sank or sits sideways
The pale layer can float, sink or sit sideways. Its position does not show whether the SCOBY is healthy; use aroma, temperature, time and pH together.
Still sweet after several days
Check the actual temperature and pH trend. A cool room, too little starter liquid or a weak SCOBY can slow acidification.
pH remains above 4.2 on day 7
Discard the batch. Restart with a fresh, healthy SCOBY and the full measured amount of mature starter liquid.
pH has fallen below 2.5
For a conservative beginner approach, do not drink it. Discard and shorten the next ferment.
Dry fuzzy or raised coloured patches
Blue, green, grey, brown, black or white fuzzy growth is mould. Discard the liquid and SCOBY, then clean and sanitise the equipment.
Fruit flies, eggs or larvae
Discard everything. Replace or improve the cover before starting again.
Rotten, putrid or cheesy smell
A repellent smell is not normal tartness. Discard the batch, including the liquid and SCOBY layer.
A bottle gushes when opened
Chill unopened bottles for 12–24 hours. Next time use less fruit or sugar and shorten the warm stage.
Do not scrape mould away, add vinegar, or reuse any part of a contaminated SCOBY—the liquid or the pale layer. Acidity does not make visible contamination safe.