acidulate

Verb

acidulate (third-person singular simple present acidulates, present participle acidulating, simple past and past participle acidulated)

1. (transitive) To make something slightly, or moderately acid; to acidify
2. (transitive) To make sour in a moderate degree; to sour somewhat
3. (transitive) To use an acidic catalyst. The chemical change being emphasised over the importance of the change in ph. Used in the processing of biodiesel co-products.