SpiceHQSearch

Pounding and stone-grinding

Also called mortar and pestle, pestle and mortar, stone grinding, wet grinding, grinding stone

Quick answer

Crushing spices and aromatics against stone — in a mortar or on a flat grinding stone — rather than cutting them, so that cells are burst rather than sliced.

What it does to spices

Pounding and stone-grinding break plant material by crushing and shearing, which ruptures cells and releases their oils and juices into the paste, where a blade tends to cut cleanly through and leave more of them intact. That is why a pounded Thai curry paste, a sambal-like chilli relish or a ginger-garlic paste made on a stone is more aromatic and holds together more smoothly than one made in a blender, and why the traditions that make pastes have kept their stones. It is also slower and cooler: a mortar does not heat the paste the way a fast blade can.

Culinary conventionThe traditions of Thailand, Indonesia, Mexico and South Asia describe the difference consistently, and it follows from the cell-rupture mechanism recorded below.Sources: On Food and Cooking: The Science and Lore o…

Why it works

Aroma compounds in herbs and rhizomes are held in oil cells and glands. Crushing bursts them wholesale and mixes their contents with the surrounding plant juices, releasing aroma quickly; where enzymes are held apart from their substrates, as in garlic and mustard, crushing also brings the two together and starts the reactions that make pungency. A blade leaves more cells whole and incorporates air, which is the source of the flatter, sometimes oxidised taste of a machine-made paste.

Reasonable evidenceSources: On Food and Cooking: The Science and Lore o…; Chemistry of Spices

How it goes wrong

  • Adding everything at once: hard, fibrous aromatics such as lemongrass and galangal go in first, soft and wet ones last.
  • Pounding wet ingredients before dry ones, which makes the dry ones slide rather than break.
Culinary conventionStandard order of work in the paste-making traditions, following from how hard and wet material behave under a pestle.

Spices it matters for

What it changes in the spice

The chemistry this technique sets off, explained in full on the science page.

What has been measured

Findings from studies and documented practice that concern this technique, each with the conditions it was made under and what it does not show.

Grinding

Fennel seed, Cinnamon (Ceylon), Cloves, Ginger, Korarima

Spice users in the markets of Wolaita, southern Ethiopia, describe mekelesha as fennel seed, cinnamon, clove, ginger, cardamom and pepper ground together in a mortar and pestle into a powder, which is added to doro wot. The same informants grind ginger, rue seed and garlic in a mortar for the fresh sauce datta.

Traditional practiceDocumented as practice in a published ethnobotanical study of two Ethiopian spice markets. It records how the mixture is made; it does not measure what hand-grinding does to the spices.Sources: Diversity of Spice Plants, Their Use and Fu…

Conditions: Whole dried spices ground together by hand in a mortar and pestle

What this does not show: What the informants of one district say, with no proportions, particle size or timing. It does not show that pounding gives a different result from milling.

Documented practice

What it is called

The same technique in the traditions that use it, each named in its own terms.

  • Krok

    Thai

    The deep clay or granite mortar in which curry pastes and som tam are pounded.

  • Cobek and ulekan

    Indonesian

    The shallow stone bowl and pestle for sambal and bumbu.

  • Molcajete

    Mexican

    Volcanic-stone mortar for salsas and spice pastes.

  • Sil-batta

    South Asian

    A flat grinding stone and rolling stone, used wet for masalas and chutneys.

  • Batán

    Andean

    A flat stone with a rocking upper stone, for ají and herb pastes.

  • Suribachi

    Japanese

    A ridged ceramic bowl with a wooden pestle, used for sesame.

The tools it is done with

The equipment used for this technique, and the forms it takes in the kitchens that use it.

  • Mortar and pestle

    Also called pestle and mortar

    A heavy bowl and a pestle used to pound, crush and grind. Pounding tears and bruises rather than cutting, working oils and juices out of the material and into one another, which is why the pastes of Thai, Malay and Indonesian cooking and many salsas are traditionally made this way rather than in a blade grinder.

    Culinary conventionEveryday kitchen equipment in the traditions named, described as it is used; no single publication is the authority for it.
    What it does to a spice:

    Crushing spices at the moment of use releases their aroma into the dish rather than into the air of a storage jar, and pounding fresh aromatics with salt or spices yields a paste in which they are bound together — a different texture from the finely cut purée a blade makes.

    Culinary conventionFollows from what crushing does to oil cells, recorded on the grinding and pounding techniques and in the ground-spice staling transformation.
    History:

    Mortars and pestles survive from ancient Egypt — one of travertine is dated about 1550–1300 BCE, another of limestone about 1300–1080 BCE — from Iran, where a bronze mortar inlaid with silver was made in the late 12th or early 13th century, and from 15th-century northern Germany, in bell metal. A stone set from Nubia is older still, about 3100–2649 BCE, and a double-sided stone mortar was made in India in the 17th century. Their catalogue records do not say what they ground; of a small Chavín-style stone mortar from Peru, of 700–1 BCE, its museum suggests pigments or ritual plants and not food.

    Reasonable evidenceSources: The Metropolitan Museum of Art — Collection… (Object 13.125.15a, b: mortar and pestle, Nubia, ca. 3100–2649 B.C., stone); The Metropolitan Museum of Art — Collection… (Object 2018.858a, b: double-sided mortar and pestle, India, 17th century, stone); The Cleveland Museum of Art — Open Access c… (Object 1957.494: feline mortar and pestle, Peru, 700–1 BCE; catalogue description); The Metropolitan Museum of Art — Collection… (Object 554684: mortar and pestle, Egypt, ca. 1550–1300 BCE); The Metropolitan Museum of Art — Collection… (Object 568591: mortar and pestle, Egypt, ca. 1300–1080 BCE); The Metropolitan Museum of Art — Collection… (Object 444529: mortar and pestle, Iran, late 12th–early 13th century); The Metropolitan Museum of Art — Collection… (Object 468675: mortar, North German, 15th century)
    • Molcajete and tejolote (Mexico) — A three-legged bowl of rough volcanic stone with its pestle, used for salsas and for grinding spices and chillies.
    • Suribachi and surikogi (Japan) — A glazed earthenware bowl with a combed, ridged interior and a wooden pestle, used for sesame and other seeds.
    • Krok and saak (Thailand) — A deep mortar of clay or granite for pounding curry pastes and salads.
    • Lesung and ulekan (cobek) (Indonesia and Malaysia) — Stone mortars and pestles, often shallow, for the spice pastes of the region.
    • Okhli and musal (India) — A deep mortar, often set into the ground or made of stone or wood, with a long pestle for pounding grain and whole spices.

    Used for Garlic, Black pepper, Green cardamom, Cumin, Coriander seed, Lemongrass, Galangal, Sichuan pepper

  • Grinding stone

    Also called saddle quern, grinding slab

    A flat or slightly hollowed stone on which spices, aromatics and grains are ground by rubbing or rolling a second stone across them. Where wet spice pastes are central to a cuisine, the stone was the standard means of making them before electric grinders, and it remains in use.

    Culinary conventionEveryday kitchen equipment in the traditions named, described as it is used; no single publication is the authority for it.

    Made in granite, sandstone, travertine, volcanic stone

    What it does to a spice:

    Wet grinding on stone produces a smooth paste with the aromatics crushed rather than chopped, and does it without the heat of a high-speed blade.

    Culinary conventionFollows from the mechanism recorded on the pounding and grinding techniques; it is described as practice rather than as a measured difference.
    History:

    Grinding stones are among the oldest surviving tools of food preparation. Egyptian examples in travertine, granite and sandstone are dated from about 1981–1952 BCE to about 1300–1080 BCE. In Central America carved stone metates survive from the 1st to the 5th century onwards; the grandest, with effigy heads and openwork, were made in ancient Costa Rica, where metates served for preparing maize and the elaborate ones are read as seats and emblems of rulers. None of these records says a spice was ground on the stone it describes.

    Reasonable evidenceSources: The Metropolitan Museum of Art — Collection… (Object 08.200.15c: grinding stone, Egypt, ca. 1981–1952 B.C., travertine); The Metropolitan Museum of Art — Collection… (Object 15.3.1715: grinding stone, Egypt, ca. 1300–1080 BCE, granite); The Metropolitan Museum of Art — Collection… (Object 1993.79.1: metate, Guanacaste-Nicoya, 1st–5th century, stone); Art Institute of Chicago — collection recor… (Object 1997.66: ceremonial metate in the form of a feline, Nicoya, 500–1000; catalogue description); The Cleveland Museum of Art — Open Access c… (Object 1971.165: metate, Costa Rica, Guanacaste, 1200–1500, volcanic stone)
    • Sil and batta (sil-batta) (North and East India, Nepal, Bangladesh) — A flat stone slab and a stone rolled or rocked across it, used to wet-grind masala pastes of ginger, garlic, chillies and seeds.
    • Ammikallu (South India) — A flat grinding stone with a cylindrical roller, used for wet spice pastes and chutneys.
    • Metate and mano (Mexico and Central America) — A sloping stone slab and a hand stone, used for maize and for grinding the chillies, seeds and spices of moles.

    Used for Ginger, Garlic, Turmeric, Cumin, Coriander seed, Ancho, Pasilla

Where it is used

The pairings that specifically call for this technique.

  • Garlic with ginger — The most widely used aromatic pair in the world, and in South Asian cooking often literally one ingredient — ginger-garlic paste, pounded together and used as the base of an enormous range of dishes. Ginger is sharp and citric where garlic is sulphurous and sweet, and each covers what the other lacks.
  • Galangal with beef — Rendang and the Indonesian slow braises, where galangal survives hours of cooking better than most aromatics and keeps giving a resinous edge against a very rich coconut and beef base.
  • Galangal with lemongrass — The defining aromatic pair of Thai cooking, and they are partners precisely because they share nothing: lemongrass is citric from citral, galangal piney and camphorous from cineole. Neither substitutes for the other and a paste built on one alone is recognisably missing an axis. Recording the pair is the useful correction to the widespread assumption that they are two versions of the same thing.
  • Timur with tomato — The defining pairing of Nepali achar. Tomatoes are charred or roasted and pounded with garlic, chilli and ground timur, and the sharp citrus-and-numbing note cuts the tomato’s sweetness in a way no other seasoning in the region does. This is the relish served with momo, and the flavour most people outside Nepal first meet timur in.
  • Candlenut with turmeric — Candlenut and turmeric are pounded together in yellow bumbu and in many Malaysian rempah; the nut thickens what the turmeric colours.

Questions this page answers

  • mortar and pestle vs blender for spice paste
  • why pound curry paste
  • what is a sil batta
  • molcajete vs blender