Umami: fish sauce, miso, soy sauce

Why

During long fermentation of soya, grain or fish, proteins break down into free amino acids, above all glutamate, which the tongue perceives as umami, a savoury fullness of taste; nucleotides from meat, fish, dried mushrooms or from fermentation multiply this sensation, so a small amount of fish sauce or soy sauce deepens the flavour of the whole dish. These seasonings are above all salty, though: according to the US FoodData Central database, fish sauce contains roughly 20% salt, soy sauce about 14% and miso about 9%, so they replace part of the salt rather than add to it (Salting and seasoning card). Fish sauce and soy sauce tolerate boiling and their flavour rounds out in a long-simmered sauce, but the salt concentrates as it reduces; miso, by contrast, loses its delicate aroma with longer boiling, so it is mixed into a little warm stock and stirred into the soup only after it comes off the heat. Many of them contain allergens that must be declared on EU labels: soy sauce and miso contain soya and often wheat or barley, fish sauce fish, oyster sauce molluscs and shrimp paste crustaceans.

How to do it

• Count fish sauce and soy sauce as salt: a tablespoon of fish sauce carries about 3.5 g of salt, a tablespoon of soy sauce about 2.2 g; add the recipe salt only after tasting.
• Add fish sauce or soy sauce to long-simmered sauces and stocks in portions and adjust the seasoning only at the end, when the dish has its final consistency.
• Mix miso into a ladle of warm stock and stir it into the soup off the heat; after that only keep the soup hot, do not boil it.
• If a dish with fish sauce is salty but flat, add acid and a little sugar, such as lime and palm sugar, not more salt.
• Look for allergens on the label: soya and gluten-containing grain in soy sauce and miso, fish in fish sauce, molluscs in oyster sauce; treat tamari as gluten-free only if labelled so.
• Store opened seasonings as the label says, miso and oyster sauce in the fridge; miso keeps longer if you use a clean spoon.

If it goes wrong

Dilute an over-salted dish with unsalted stock, water or coconut milk and add more unsalted ingredients, or serve it with unsalted rice (Salting and seasoning card). Lime juice, a little sugar and fresh herbs soften an overly strong fishy taste. Whisk grainy miso in soup smooth or strain the soup through a sieve, and next time mix the miso separately; a spoonful of miso stirred in off the heat restores the aroma of an over-boiled soup, but only if the soup can take more salt.