With a pestle for grinding and a smooth yet firm surface inside the mortar, a mortar and pestle allows cooks to grind spices and wet or dry ingredients. Italian basil pestos, Thai curry pastes and Mexican guacamole were all traditionally made in this method. Though its modern usage is primary culinary, the mortar and pestle is historically closely associated with medicine. Its use was documented in the most remote medical writings yet discovered, dating back to 1550 B.C.E.
Wash the mortar and pestle under hot water. Place the mortar in your sink while washing, as it is heavy and can chip if it slips from your hands and falls on a porcelain sink. If the mortar is too large to fit under the faucet of your sink, soak it in a tub of water while you scrub it.
Scrub both items with a stiff brush to remove granite dust and any particles that have become stuck on the rough outside of the mortar. Rinse the mortar and pestle again and pat them dry with a dishcloth. Place in a well-ventilated area and allow to air dry completely.
Place the mortar on a stable work surface that will not crack under the pressure from pounding the mortar. Grind a handful of uncooked rice in the mortar and pestle by moving the pestle in rotating, pressured motions alternated with up and down pounding. Check the ground rice for dirt or granite particles. Repeat with handfuls of rice until the resulting rice dust is free of contaminants.
Peel the garlic cloves and place them in the centre of the mortar with a half teaspoon of salt. Crush the garlic with the pestle and grind it into a paste. If you do not have enough traction, add additional salt. Use the pestle to move the garlic around the mortar. Grind and coat the garlic over as much area inside of the mortar as your can.
Scoop out the garlic paste and wash the mortar and pestle with warm water till the wash water comes off clear. Do not use soap, particularly on the mortar, as it will remove the seasoning, and detergents and fragrances can be absorbed by the stone. Set the mortar and pestle in a well-ventilated place to air dry before the next use.
Garlic and salt is a general seasoning for a mortar, but different cuisines use different initial seasonings. In Indonesia, fresh turmeric is ground into the mortar, while sesame seeds are used in Japanese Suribachi.