Mortar and pestles come in different shapes, sizes and materials. Here’s why some are better suited to certain tasks than others:
Granite . Traditionally used in Thai cookery, especially for making spice pastes, granite mortars and pestles are some of the most versatile. Their weight and slightly irregular surface make (relatively) easy work of a variety of jobs, such as crushing dried chili peppers and spices, and grinding herbs and even fibrous ingredients such as kaffir lime leaves and lemon grass.
Marble . A heavy bowl made of the snowy, veined stone is great for crushing spices, pounding garlic and ginger, etc., but the super-smooth surface means it doesn’t work quite as well for crushing herbs, nuts and seeds, which tend to dance around.
Olive wood . Mediterranean cooks traditionally used wooden mortars for crushing spices and making garlic sauces, whose flavor tended to linger in the bowl — which can either contribute complexity of flavor over time or imply a flavor of garlic where it’s not welcome. Choose a wooden mortar if you’re planning to use it repeatedly for the same purpose.
Cast iron . The heavy, durable material can be a good choice for processing hard and fibrous ingredients, but it can rust and so requires a little extra care. Avoid iron mortars with a heavy coating on the inside; though they discourage rust, they create a surface too slippery to work with effectively.
Ceramic . Cooks in Europe have long favored ceramic mortars and pestles for making, say, pesto in Italy and picadas in Spain. This material works particularly well with garlic, nuts, herbs and bread. In Thailand, a ceramic mortar and pestle is used to lightly bruise ingredients for green papaya salad.
Japanese earthenware . In Japanese cooking, the mortar and pestle known as a suribachi is used for grinding seeds, nuts and tofu, and for crushing ginger, fish and meat into paste. It’s also a great choice for making pesto or other crushed-herb blends because of its ridged interior.