Kapi, or shrimp paste, is a fundamental – and incredibly influential – ingredient in Thai cooking, especially Southern Thai cuisine. It’s everywhere in the restaurant where I cook in Phuket – Thai Library. Kapi is a condiment made from fermented small sea shrimp, specifically krill (known as koey in Thai), mixed with salt.
The process involves grinding, pounding, or pressing the krill with salt, then repeatedly sun-drying and fermenting the mixture until it reaches its distinctive consistency and flavour. This slow, careful process develops its unmistakable pungent smell and complex taste – deeply savoury, slightly sweet, and intensely umami.
In the South, kapi holds particular significance. It’s the primary ingredient in nearly all Southern Thai curry pastes, which are known for their intense, spicy, and robust flavours compared to other regions. Sourcing high-quality kapi is crucial for a flavourful curry – at Thai Library, we get ours from Lanta Island and Krabi provinces.
To make curry paste using kapi, you start with a pestle and mortar. While blenders are common these days, this traditional pounding technique is essential in Southern Thai cooking. It releases the oils and flavours from each spice more thoroughly and evenly than a blender ever could.
Start by pounding the harder, coarser ingredients first – dried chillies and salt (which helps with grinding) – followed by lemongrass, galangal, and makrut lime zest. Then add the softer ingredients, such as shallots and garlic, and finally, the kapi. Keep pounding until everything is thoroughly combined and the mixture is intensely aromatic.
