When your sourdough starter begins to emit an aroma reminiscent of nail polish remover, it’s a telltale sign that it’s producing a substance called acetone. This occurs when the yeast and bacteria that fuel the fermentation process are out of balance, specifically when there’s an excess of bacteria producing acetic acid. As the acetic acid builds up, it can start to convert into acetone, especially if the starter is not being fed regularly or is kept in conditions that are too warm.
Follow these steps to fix your sourdough starter:
1. Increase the frequency of your feedings.
For a starter kept at room temperature, feeding it once every 12 to 24 hours is ideal. If it’s particularly warm where you are, you might even need to feed it twice a day. During each feeding, discard about half of your starter before adding fresh flour and water. This process dilutes the acids and helps to rebalance the yeast and bacteria populations.
2. Ensure that your starter is kept at a moderate temperature.
An ideal temperature for your starter is between 68°F to 75°F (20°C to 24°C). Extreme temperatures can stress the yeast and bacteria, leading to unwanted byproducts like acetone. If your kitchen is very warm, try to find a cooler spot for your starter, or consider storing it in the refrigerator, which slows down the fermentation process significantly. Feeding a refrigerated starter once a week should suffice.
3. Be patient and persistent with these adjustments.
It may take a few days of consistent care for your sourdough starter to recover fully, but with time, it should return to its normal, pleasantly tangy aroma and be ready for baking once again.
