Historical clue formulations

• Kind of acid partly responsible for sourdough's tang — 2026-07-18
• Obtained from milk — 2022-08-29
• Kind of acid produced during exercise — 2021-04-16
• Milk-derived — 2019-02-23
• Kind of acid — 2009-08-30
• ___ acid (sour cream component) — 2009-05-10
• Milk-related — 2005-06-26
• Obtained from milk — 2004-10-17
• Milk-related — 2001-02-28