I’ve been baking sourdough for a few months now, and most days the starter smells tangy and yeasty, which feels right. But a couple of mornings this week, I opened the jar and was hit with a strong smell like nail polish remover or acetone. I’ve read that it could mean the starter is stressed or starving, but I fed it the same way as usual - equal parts flour and water, kept it at room temp around 70°F. I even tried switching to a different flour brand to see if that helped, but the smell came back. The starter still bubbles and rises, just with this weird smell. Should I be worried it’s going bad and toss it? Or can I revive it somehow? What’s the best way to fix a starter smelling like this without losing all the work I’ve put into it?

On 01/23/2026 at 10:35 PM, SunnyLife101 said:

I’ve been baking sourdough for a few months now, and most days the starter smells tangy and yeasty, which feels right. But a couple of mornings this week, I opened the jar and was hit with a strong smell like nail polish remover or acetone. I’ve read that it could mean the starter is stressed or starving, but I fed it the same way as usual - equal parts flour and water, kept it at room temp around 70°F. I even tried switching to a different flour brand to see if that helped, but the smell came back. The starter still bubbles and rises, just with this weird smell. Should I be worried it’s going bad and toss it? Or can I revive it somehow? What’s the best way to fix a starter smelling like this without losing all the work I’ve put into it?

That acetone smell is definitely a sign your starter is running low on food and producing those funky byproducts. Even if you’re feeding it the same way, sometimes the balance of yeast and bacteria shifts, especially if the temperature or humidity changes a bit. I’d try discarding most of the starter and feeding it fresh flour and water more frequently - maybe twice a day for a couple of days - to help it bounce back.

Also, some folks find switching to whole grain flours like rye or whole wheat can give the starter a nice boost since they have more nutrients. Just keep an eye on the smell and bubbles; if it’s still rising well and smells more pleasant after a day or two, you’re probably in the clear. No need to toss all your hard work yet!