Check the surface before you stir
Look at the top, the walls and the underside of the lid before moving the mixture around. Check whether a mark is on the wet starter itself or appears to be dried residue on the glass. The action to take depends on whether you can confidently identify an ordinary change. When an unusual patch remains doubtful, discard the culture.
| What you see | What to do |
|---|---|
| Fuzzy or hairy growth, including a pale patch | Discard all of the starter. |
| Unusual pink or orange streaks or spots | Discard all of the starter. |
| A surface film or patch you cannot identify | Discard it if contamination is suspected or you remain unsure. |
| Smooth liquid on a familiar mature starter after a long gap | It may be hooch. Inspect the whole jar for other changes before following your usual feed routine. |
A clean-looking spot elsewhere in the jar offers little reassurance once you suspect mold. Throw away any portion already separated from that same culture. Keep raw starter away from tasting spoons. Raw flour can carry germs even when the jar looks ordinary. [1] [3]
What about hooch or dried starter on the rim?
Hooch can form as a layer of liquid on an established starter that has been left unfed. It can look grey or dark. That appearance is different from a patch with texture or raised fuzzy growth. If there are both liquid and suspicious signs, discard the starter. A photo, colour or smell alone cannot tell you that it is safe to keep. [1] [4]
A smear that has dried above the starter line can leave a pale crust on the wall. Clean walls make it easier to tell which marks are old. An unfamiliar film or new patch in an otherwise ordinary jar still calls for caution. If you are uncertain about a change, starting with a clean jar is the simplest way to resolve it.
Clean the jar and start over
Empty the starter into the waste. Wash and rinse the container and utensils thoroughly, then clean the work surface and wash your hands. Use fresh flour and water and clean equipment if you start another culture. You can also get a portion of a known healthy starter and put it into a clean jar. Use a loosely covered container with headroom for the next feed. [1] [3]
A dated feed and a clean starting line can help if the next jar changes unexpectedly. Crispy Crust’s planned starter history would let you keep a note of the last feed and consult reviewed guidance. The discard decision still belongs with what you know about the jar and what you see.
How can I make changes easier to spot next time?
Date the jar after feeding and wipe away fresh smears above the level. Use a clean spoon each time and follow a care routine that suits where you store it. If the jar is going into the fridge, note when you plan to inspect and feed it again. These habits make the jar easier to read when you return. [1] [5]