It's common for people to mistake bits of culture - or SCOBY - for mold, so don’t assume! Mold on kombucha tends to grow on the surface of the liquid, and it looks much like the mold you might see on too-old foods in your fridge.Kombucha Kamp, a wonderful resource for home-brewing, includespicturesto help you determine whether what you are seeing is mold or culture. If you determine you have moldy kombucha, toss it - including the SCOBY. Don’t worry - you can always grow a new one using a bottle of Buchi! If you’re not sure even after consulting pics, the safest thing is to toss the questionable batch and begin again.