Anonymous wrote:The acetone smell is from yeast fermentation. Not sure why pasta salad would have that, but look it up. Usually happens in bread products

The acetone or nail-polish-remover-like smell in sourdough starters is caused by the presence of the species of bacteria known as Acetobacter. These bacteria are responsible for producing acetic acid, which is one of the primary acids produced during the fermentation process in sourdough starters. As the bacteria produce acetic acid, they also produce small amounts of acetone as a byproduct.