Kosho is a fermented paste made from yuzu, salt and chilli. Yuzu is a uniquely Japanese citrus fruit, notoriously difficult to grow. The flavour of yuzu is somewhere between lime, grapefruit and pomelo, however it is much more intense and sour.
Kushino Farms make their kosho by salting and fermenting the yuzu peel and chillies separately for a year. They are then gently ground (using no heat at all) and blended together.
Just a tiny amount of Kosho adds a huge fresh bright flavour burst to all kinds of dishes. It works particularly well with grilled meats and raw seafood. It also adds a bright citrusy-salty note to mild soups or sauces. Fantastic when stirred into mayonnaise or olive oil vinaigrettes.