If you check on your scoby and see that it's turned black, then the scoby has died. The best practice is to throw it away and any batch of tea that was made using it. A dead scoby does not necessarily mean that you did something wrong. Remember, it's a living organism and has a lifespan.

How do you know if SCOBY is bad?

A SCOBY can have streaks of brown or black on it – this is just leftover remnants of tea from the last brew. You can tell if a SCOBY is moldy by the presence of mold. And mold does NOT look like leftover tea bits. A moldy SCOBY has white or gray fuzzy growths on it.

What does a spoiled SCOBY look like?

A moldy or dead scoby is quite distinctive, and there is no mistaking it when you see it. The mold will be white or colorful, fuzzy and dry. It can appear as spots on the scoby, or cover the scoby altogether. A dead scoby will be black.