Souring

Lemon juice is a natural fruit-based acid.

Souring is a food preparation technique that causes a physical and chemical change in food by exposing it to an acid. This acid can be added explicitly (e.g., vinegar, lemon juice, lime juice, etc.), or can be produced within the food itself by a microbe, such as Lactobacillus.

Souring is similar to pickling or fermentation, but souring typically occurs in minutes or hours, while pickling and fermentation can take a much longer amount of time.