Crab paste is a condiment made by salting and preserving crab meat in a flavorful concentrate which can be used in a variety of dishes. The food is most associated with Asian cuisine, which features an assortment of preserved seafood pastes and sauces. Many Asian grocery stores carry this condiment, as do some specialty purveyors. In addition to being used in Asian dishes, crab paste can also be used to season food from other cultures as well, and can substitute for anchovies, fish paste, and similar ingredients.
To make crab paste, fresh crab meat is either salt dried or wet fermented with a large amount of salt to keep it free of bacteria. Once it has cured, it is packaged in tubes or containers which are typically designed to be resealed, since only a small amount of paste is needed at a time. The high salt content keeps the paste usable, as long as it is stored in a cool dry place.
Soups, stews, curries, and sauces throughout Asia use crab paste. It can also be used in marinades and dressings for a wide range of foods. The intensely salty flavor goes a long way, so most cooks use this ingredient sparingly, in amounts which will bring out the flavor of the food without being overwhelming. When fermented crab meat is used, the paste will have a slightly sour flavor, while dry salted crab meat will have a cleaner taste.
Fermented foods have been used as condiments for thousands of years, since salting and fermentation act as preservatives, allowing people to have access to foods year round, rather than just in season. Some other examples of fermented seasonings are soy sauce, sauerkraut, and kimchi. Fermentation is also used as part of the processing of foods like coffee, chocolate, cheeses, and of course beer and wine. As many observers have noted, fermented foods usually taste sour, and there can sometimes be a thin line between foods which have gone bad and foods which are still edible.
Asian cuisine in particular features a number of fermented foods, and crab paste is a fairly tame representative of this food group. Others have much more pungent, intense flavors which some Westerners do not enjoy, although many Asians have acquired a taste for these unique flavors. Starting with crab paste is a great way to begin to experiment with the wide range of interesting fermented ingredients in Asian cuisine.