Mizu-yokan is Japanese confectionery, and is a type of yokan (azuki-bean jelly).
Process of making
The typical way of making mizu-yokan is similar to that of regular yokan, which is to mix sugar and bean jam together and make it hard by cooking with agar. Mizu-yokan is softer than regular yokan because it is made to contain more water. Generally ogura-an (sweet azuki bean paste containing both mashed and whole beans) is used for making mizu-yokan, but sometimes white bean jam is used instead. Another way of making mizu-yokan is to use brown sugar instead of bean jam.
First, soak a bar of agar in water and tear it into small pieces, and boil it in a pan with water (500-600cc of water per one bar of agar). When the agar is dissolved, add sugar and bean jam in the pan (in some cases, also add powdered arrowroot mixed with a little water) and heat it to a boil again. Cool the material in the pan, strain it, put it in a container and allow it to cool until it becomes hard.
Most mizu-yokan is sold in an aluminum can or a plastic cup. Some fancy confectioners sell mizu-yokan contained in a bamboo cylinder. Mizu-yokan used to be made in a large wooden container and sold by the piece. As a vestige of that, some stores in Fukui Prefecture and Ishikawa Prefecture make mizu-yokan in a paperboard container to sell.
Mizu-yokan is often eaten chilled in summer, and it is also a kigo (a season word) of summer for haiku (Japanese seventeen-syllable poem). However, mizu-yokan is mostly eaten in winter in places like Fukui Prefecture, Osaka Prefecture (in the Nose-cho area), Kyoto Prefecture (in the Kameoka City area), Ishikawa Prefecture (in the Wajima City area), Niigata Prefecture (in the Joetsu City area), Yamagata Prefecture (in the Tsuruoka City area), and Tochigi Prefecture (in the Nikko City area).
Mizu-yokan made in Fukui Prefecture is very different; it is made with brown sugar and agar, and the texture is extremely soft since it contains a lot of water.
In Fukui Prefecture, Kameoka City (Kyoto Prefecture), and Nose-cho (Osaka Prefecture), mizu-yokan is sometimes called detchi-yokan (cheap yokan containing less azuki beans and sugar). The making process and texture are very different from detchi-yokan made in Kyoto Prefecture and Omihachiman City, Shiga Prefecture. Detchi-yokan made in Nara Prefecture and in the Iga district in Mie Prefecture is similar to the mizu-yokan made in Fukui Prefecture.