Crushing, cracking and bruising

Also called cracking, bruising, cracked, bruised

Quick answer

Breaking a whole spice or aromatic partly open — a bruised cardamom pod, cracked peppercorns, a crushed garlic clove — without grinding it to powder.

What it does to spices

Crushing sits between whole and ground. A bruised cardamom pod or lemongrass stalk releases aroma into a pot while staying large enough to lift out; cracked peppercorns give bursts of heat and aroma in a crust rather than an even dusting; a clove of garlic crushed rather than sliced becomes markedly sharper, because breaking its cells starts the reaction that makes allicin. For spices whose pungency is made on damage — garlic, mustard, horseradish — how the spice is broken sets how hot it becomes.

Culinary conventionFollows from the damage-triggered reactions recorded on the garlic and mustard transformations, and from ordinary practice across the cuisines that use whole spices in braises and crusts.On Food and Cooking: The Science and Lore o…

Why it works

Breaking the seed coat, pod or cell walls exposes the oil cells beneath to air and to the cooking liquid, so aroma leaves faster than from an intact spice and more slowly than from a powder. In garlic and in the mustard family, damage also mixes enzymes with the precursors they act on — alliinase with alliin, myrosinase with glucosinolates — which is why the degree of damage controls pungency.

Strong evidenceOn Food and Cooking: The Science and Lore o…; Chemistry of Spices

How it goes wrong

Crushing garlic finely for a long, gentle cook, which makes it harsher than slicing would.
Cracking pepper too far in advance, which loses its top notes before it reaches the pan.

Culinary conventionFollows from the damage-triggered pungency and the volatility recorded above.

Spices it matters for

Green cardamom — Pods bruised so the seeds can perfume rice or a braise, then picked out.
Black pepper — Cracked for a steak or duck crust.
Garlic
Mustard seed — Pungency appears only once crushed seed meets moisture.
Juniper — Lightly crushed before going into a braise or marinade.
Lemongrass — Bruised with the back of a knife before infusing.

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.

Crushing and cutting · Converts 1-Propenyl cysteine sulfoxide, Propyl cysteine sulfoxide, Methyl cysteine sulfoxide, Pyruvate, enzyme activity

Onion

When an onion is crushed, the precursor responsible for its tear-producing effect, 1-propenyl cysteine sulfoxide, is consumed almost at once: its hydrolysis was close to complete between 5 and 20 s after maceration. The other two flavour precursors, the propyl and methyl compounds, were only about half consumed after 5 s and reacted no further. How much of each was present, and how far each reacted, depended on the cultivar and on the sulfur the plant had grown with.

Reasonable evidenceDifferential hydrolysis of alk(en)yl cystei…

Conditions: Measured from 5 s to 2 h after maceration · Rapidly macerated bulbs; precursors by HPLC

What it means in practice:

The sharpest part of an onion’s chemistry is over within seconds of cutting, so nothing done to the cut onion afterwards can prevent it; only what is done before cutting can.

Culinary conventionAn inference from the measured speed of the reaction.

What this does not show: Read in the abstract only. Bulbs macerated completely in the laboratory, which breaks far more cells than a knife; the volatile products themselves were not measured.

Measured on the spice

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

Where it is used

The pairings that specifically call for this technique.

Mustard seed with pork — Mustard's sharpness cuts pork fat directly. Its pungency develops only when the crushed seed meets moisture, so it behaves quite differently from a dry aromatic spice.
Black pepper with beef — The definitive beef spice in European cooking, to the point that steak au poivre is built on nothing else. Beef has enough flavour of its own to argue with most spices; pepper's pungency sits alongside it rather than covering it.
Green cardamom with rice — Bruised pods cooked with rice perfume the whole pot and are easily picked out. Standard in biryani, pulao and Persian rice.
Black pepper with duck — Duck is dark and mineral enough to take pepper at a level chicken cannot, and cracked pepper on a scored duck breast is close to a default. The piperine reads as warmth against the fat rather than as sharpness.

Questions this page answers

should I crush or grind cardamom
how to bruise lemongrass
cracked pepper vs ground pepper