Singapore Quality typically refers to 99% or 98% purity, allowing for a small amount of stems and foreign matter, suitable for general grinding. "Europe Quality" usually refers to 99.5% purity or higher, often machine-cleaned and Sortexed, with strict limits on pesticide residues.

Adulteration often involves grass seeds that look similar but crush easily into dust, or spent seeds (seeds used for oil extraction) which are lighter and have no smell. A simple water test or visual inspection for weight and aroma can reveal this.

This depends on the origin and age. Fresh Indian cumin is typically greyish-brown. Turkish or Syrian cumin can be darker. Old cumin turns very dark brown or blackish and loses its fresh aroma.

Like most spices, they don't spoil in a way that makes them unsafe immediately, but they lose potency. Best used within 18-24 months. The essential oils responsible for the flavour will fade over time. Always verify the harvest year before you Buy Cumin in bulk.

Cumin is an extremely weather-sensitive crop. It is prone to diseases like blight if it rains during the harvest season (Feb-March). Since India produces the majority of the world's supply, a single bad weather event in Gujarat can double global prices in weeks.