A pestle is a club-shaped tool used for crushing and grinding things into powder or paste. You hold it in your hand and press down hard while moving it in circles inside a bowl called a mortar.

Together, the mortar and pestle work like a low-tech blender. Cooks use them to grind spices like peppercorns or cinnamon sticks into fine powder, or to mash garlic and herbs into paste for cooking. Pharmacists once used mortars and pestles to grind medicines and mix ingredients before pills were made in factories. Even today, chemists and scientists use them to prepare samples for experiments.

The pestle does the active work while the mortar holds everything in place. You grip the thick end of the pestle and use the rounded bottom end to press and twist against whatever you're grinding. With enough pressure and patience, hard seeds become powder and tough leaves become smooth paste.

Though we now have electric grinders and food processors, many cooks still prefer using a mortar and pestle because it gives them more control over texture and releases the flavors of spices more effectively.