Yokan is a Japanese jelly-like confectionary, normally uses sweet red bean paste poured into a mould, and harden with agar. There are neri-yokan which uses larger amount of agar, and mizu-yokan which uses less agar. The word “neri” means knead, and “mizu” means water. Neri-yokan is usually firm, and mizu one is usually softer. There is also a way to use flour or starch powder instead of using agar, and by steaming to harden the bean paste, which is called mushi-yokan.
The typical one is square shaped, by pouring the ingredients in square mould. The one made in the early days were basically mushi-yokan, and neri-yokan only became popular after the Edo period (1603-1867). Mizu-yokan used to be eaten as part of new years dish, and was made during winter. However, mizu-yokan is now often eaten as cold sweets in summer by refrigerating it.
The ingredients and additives of yokan varies. Instead of using red bean paste, white kidney beans are used to make white one. White one can be colored with red color additives, and white and red one is sometimes served as a good fortune food for new years, because red and white color is considered to bring good luck.
Chestnut which is steamed or sweetly boiled are often mixed in the bean paste. Mashed chestnut are also used as a main ingredient instead of bean paste, and is called kuri-yokan. There is imo-yokan which uses steamed sweet potato mixed with sugar, filled into a square mould, and harden by cooling down. Green tea powder is often added to color one vividly and to give a refreshing flavor.