Smell decoder
My sourdough starter smells like…
Smell is the most reliable signal a starter gives you, and almost none of the alarming ones mean anything is wrong. Five of the six things a starter can smell like resolve to the same instruction: feed it more often. The sixth is worth a look in the jar first.
Type above, or pick from the list below. Every smell has its own answer.
Six families, 168 descriptors. Tap any one for the verdict.
Actually fine, no action needed
It's fine. That's a healthy starter.
Solvent
It's fine. Your starter is hungry.
Alcohol and brewery
It's fine. Same cause, milder.
Vinegar and dairy
It's fine. This one is about flavour, not safety.
Feet and socks
It's fine. Every starter does this.
Genuinely worth a second look
Stop and check for mould before you feed it.
The only question on this page that has a yes. Fuzzy, raised, or coloured means throw the jar out. Everything else does not.
That's hooch, and it's alcohol rather than anything sinister. Pour it off for a milder starter, stir it in for a tangier one.
Every failure this site can diagnose, in one list, in your own words.