The word 'kaeshi' is an abbreviation of 'nikaeshi', a seasoning used as a soba (buckwheat noodles) dipping sauce. Soba dipping sauce is made by mixing water with kaeshi. The sauce used before mixing with soup for ramen (Chinese soup noodles) may also be called kaeshi.
Kaeshi for Soba
Made by adding sugar and mirin (sweet cooking rice wine) to soy sauce before leaving to stand for a while. It is allowed to stand in order to mellow the soy sauce give it a mature flavor. The same basic ingredients can be used to create three different sauces depending on the preparation method.
- Adding sugar and mirin to heated soy sauce.
- Heating sugar and mirin to make starch syrup, and blending it with unheated soy sauce.
- Heating a small amount of soy sauce and adding sugar and mirin to it, then blending it with unheated soy sauce.
Restaurants make their own kaeshi, and the recipe and preparation method are often kept secret because it defines a restaurant's taste more than stock. In addition, the soup mixing soup stock containing large amount of Kaeshi for dipping soba is called Karatsuyu (spicy soup), and the soup mixing soup stock containg small amount of Kaeshi for hot soba is called Amatsuyu (mild soup). Karatsuyu and Amatsuyu use defferent soup stock in some cases.
Once again adding mirin to kaeshi and letting it stand produces what is called gozen-gaeshi or uwa-gaeshi, which is used to make zaru-soba (soba topped with sliced nori seaweed served on a latticed bamboo tray) sauce. As indicated by its name uwa-gaeshi (lit. top kaeshi), it is the top grade and richer than ordinary kaeshi. However, only difference between mori-soba (soba served on a small wickerwork tray) and zaru-soba is the addition of sliced nori seaweed in most restaurants today, and very few restaurants serve zaru-soba using gozen-gaeshi.
Kaeshi for Ramen
Originally referred to a soy-based sauce, and most restaurants used a sauce made by boiling down broth of roast pork. Though most restaurants make their own soup today and the recipes vary greatly from restaurant to restaurant, it is basically made by boiling down with ingredients which release soup stock. As the variety of tastes of ramen has increased, it is also used as a collective term for sauce including miso-dare (miso-based sauce) and shio-dare (salt-based sauce).