Does flour need a hechsher?

Answer: No (cRc).

Reason: Plain flour does not need certification.

Source:

• cRc: flour is acceptable without a hechsher.

Related questions:

• Do cornmeal and cornstarch need a hechsher? No (Star-K, cRc).
• Does pasta need a hechsher? Raw, unflavored pasta made only of flour and water: no (cRc).
• Do oats need a hechsher? No, if plain (Star-K, cRc).

References: cRc (askcrc.org), “Flour”