Citric acid, also known as “sour salt,” is a colorless, weak, organic acid. I know, it sounds like a poisonous substance, but it’s a low-level acid that’s both safe and strong enough to ...

For example, in this recipe for Canned Tomato Passata, the citric acid helps decrease the pH levels of the tomatoes and make the passata safe to can. "It inhibits any kind of bacterial growth.