Kapi (Shrimp Paste)

Kapi is made by salting tiny shrimp or krill, pounding or grinding them into a dense paste, and then sun-drying and fermenting the mixture for weeks to months. The result is a stiff, claylike paste ranging in color from pale pink (fresh, lightly fermented) to deep purple-grey or mahogany (fully aged). During fermentation, protein-digesting enzymes break down the shrimp proteins into free amino acids — primarily glutamic acid and inosinic acid — producing one of the most concentrated natural sources of umami flavor known. The smell of raw kapi is aggressively pungent and funky; once cooked, it transforms almost entirely, leaving behind a savory, deeply marine richness that underpins the dish without announcing itself. Kapi is indispensable to Thai cuisine. It is a foundational ingredient in virtually every Thai curry paste (nam phrik kaeng): red, green, yellow, massaman, and panang curry pastes all include kapi among the first ingredients pounded in the mortar. Nam phrik kapi — a relish of pounded kapi, lime juice, palm sugar, and fresh chilies — is one of the most elemental condiments in Thai cooking, served with raw vegetables, fried fish, and rice. Kapi also features centrally in the Lao and Thai fermented-paste relish (pounded into raw nam phrik), in pad krapow (stir-fried basil dishes), and in the coconut-milk-based salad dressing yam. Cooking kapi before adding it to a dish is almost always recommended. The most common method in Thai cooking is dry-roasting: a small ball of kapi is wrapped in a banana leaf or foil and held over a flame or set on a dry skillet for one to two minutes per side until aromatic. This technique, called kapi ping (กะปิปิ้ง), burns off some of the raw ammonia-forward volatiles while driving the Maillard reaction on the amino acids and sugars in the paste, producing roasted, almost caramelized top notes. When kapi is pounded directly into a curry paste that will itself be fried in coconut cream, a separate roasting step is often skipped — the frying of the paste in hot fat serves the same purpose. Quality varies significantly between brands. Thai-produced kapi, particularly from coastal Rayong and Samut Songkhram provinces, is considered finest: it is made from a specific small shrimp called kung hom (โกong หhom) and has a slightly sweeter, more nuanced flavor than the cruder shrimp pastes from other origins. When substituting with Malaysian belacan (which is drier and more concentrated) or Filipino shrimp paste, reduce quantities by about a third. Storage: kapi is shelf-stable at room temperature if sealed tightly, but refrigeration extends quality and drastically reduces ambient odor. Always store in an airtight container.

“She flattened a teaspoon of kapi into a small foil packet, held it over the gas flame with tongs for ninety seconds per side until fragrant, then added the roasted paste to the granite mortar along with lemongrass, galangal, and dried chilies.”

• TechniqueFermentation
• TechniqueCurry Paste Grinding
• ConceptUmami

1. 1.Simple Thai Food — Leela Punyaratabandhu (Ten Speed Press, 2014)
2. 2.Thai Food — David Thompson (Ten Speed Press, 2002)
3. 3.The Food of Southeast Asia — Wendy Hutton (Periplus, 2007)
4. 4.On Food and Cooking — Harold McGee (Scribner, 2004)

Confidence: high