What’s wrong with my kombucha?

Your SCOBY hasn't had enough time to convert the sugars. This is one of the most common issues for beginners.

1. 1Move the jar to a warmer spot — keep it above 70°F (21°C) minimum, ideally 75–85°F (24–29°C). Below 70°F fermentation stalls and mold risk rises.
2. 2Leave for 2–4 more days and taste daily.
3. 3Ensure the cloth cover is breathable but not too loose.
4. 4Check that your SCOBY looks healthy and smells vinegary.

Fermentation went too long or the temperature was too warm. The bacteria have converted most of the sugar to acids.

1. 1Use it as a starter liquid for your next batch — it's very potent.
2. 2Dilute with sweet tea (1:3 ratio) to taste.
3. 3Try using it in salad dressings or marinades.
4. 4For future batches, start tasting at day 7 and shorten F1.

Not enough residual sugar for secondary fermentation, or the bottle wasn't sealed properly during F2.

1. 1Add 1 tsp of sugar or fruit juice per 16oz bottle.
2. 2Seal tightly and leave at room temperature for 2–3 more days.
3. 3Burp bottles daily to check carbonation pressure.
4. 4Ensure you're using bottles designed for carbonated drinks.

Mold is the one issue that cannot be salvaged. It appears as fuzzy growth (not smooth like a SCOBY hotel) in colors like black, green, or pink. Mold thrives when fermentation temperature drops below 70°F — the SCOBY acidifies the brew too slowly to outcompete it.

1. 1Do NOT taste or consume — discard the entire batch.
2. 2Discard the SCOBY if mold is present on it.
3. 3Sterilize all equipment with boiling water or food-safe sanitizer.
4. 4Start fresh with a new SCOBY from a trusted source.
5. 5Keep your next brew above 70°F (21°C) — the SCOBY outcompetes mold at warmer temps. Aim for 75–85°F for a healthy, fast ferment.

This batch can’t be saved — discard it and start fresh.

Kahm yeast is a flat, white, papery or powdery film that forms on the liquid surface. Unlike mold, it is NOT fuzzy and has no raised texture. It is harmless but can cause off-flavors if left unchecked.

1. 1Skim the white film off the liquid surface with a clean spoon.
2. 2Taste the kombucha — if it tastes normal, it is likely fine to drink.
3. 3Increase airflow: ensure your cloth cover is breathable.
4. 4Lower the temperature slightly if the fermentation vessel is very warm.
5. 5Use more acidic starter tea next batch to prevent recurrence.
6. 6If off-flavors develop or the film returns after skimming, discard and start fresh.

Unusual smells can have multiple causes — yeast overgrowth, contamination, or unusual tea/flavors interacting.

1. 1Taste a small amount — if it tastes OK, it probably is OK.
2. 2Check for yeast strands (brown, stringy — completely normal).
3. 3Ensure your SCOBY isn't contaminated with non-tea ingredients.
4. 4Review any flavors added — some herbs can smell unusual.