Answer: Single plain spices: no (cRc). Spice blends: only product by product (cRc).
Reason: Single ground or whole spices are fine, but blends can contain kosher-sensitive ingredients.
Source:
- cRc: single spices such as black pepper and cinnamon, ground, chopped, powdered or whole, are recommended even without hashgachah.
- cRc: spice blends are recommended product by product; a blend is acceptable only if every spice in it is acceptable without certification and it has no kosher-sensitive ingredients.
Related questions:
- Does salt need a hechsher? No (Star-K, cRc).
- Does sugar need a hechsher? No (Star-K, cRc).
References: cRc (askcrc.org), “Black Pepper” · cRc (askcrc.org), “Cinnamon” · cRc (askcrc.org), “Spice Blends (Policy)”
