Liquid on a Sourdough Starter

Have you ever noticed a grey-like liquid forming on the top of your sourdough starter but didn't know what it was or if your starter is still OK to use?⁠

This liquid (which also often has a strong aroma) is an indication that an excess of alcohol has been produced as a by-product of the yeast fermentation in your starter. It often appears if the starter is ‘hungry’ because it has been left for long periods of time without feeding or if it just requires more frequent feeding (which is usually because it is fermenting at a faster rate due to being kept at higher temperatures than usual).⁠

If there is only a thin layer, you can either stir this liquid back into the sourdough starter or drain it away before feeding it again. If you stir it through, it will add a sharper, more intense flavour to your sourdough starter and, in turn, your sourdough bread. If there is a thick layer, it is best to discard it before feeding.⁠

Your starter will usually be fine to use again (if you haven't left it for too long and it has 'died') but it may need some extra attention and love to get it back on track over the next few days with feeding it as you normally would.⁠