acetify

American Heritage® Dictionary of the English Language, Fourth Edition

1. v. To convert or become converted to acetic acid or vinegar.

Century Dictionary and Cyclopedia

1. To convert into vinegar; make acetous.
2. To become acetous; be converted into vinegar.

Wiktionary

1. v. transitive To convert into acid or vinegar.
2. v. intransitive To turn acid - Encyc. Dom. Econ

GNU Webster's 1913

1. v. To convert into acid or vinegar.
2. v. To turn acid.

WordNet 3.0

1. v. make sour or more sour
2. v. turn acidic