raindrop cake, delicate gelatinous dessert of Japanese origin that is made of spring water or mineral water and agar powder and that derives its name from its large raindrop shape. It is virtually calorie-free and has a fresh, subtle taste. Without refrigeration, the dessert loses its shape in about 30 minutes.
Called mizu shingen mochi in Japanese, the raindrop cake originated in Yamanashi prefecture, near Mount Fuji and about 145 km (90 miles) west of Tokyo. It is a variation of the traditional shingen mochi, a sweet cake made of glutinous rice flour and sugar. The raindrop cake adds water (mizu) and uses seaweed-derived agar instead of flour.
The raindrop cake was first developed in 2014 by the Kinseiken Daigahara confectioner in the small town of Hokuto, using water from the Japanese Alps; it was marketed as “water you can eat.” Molded into a raindrop shape, it was as evanescent as a rain shower, available for sale there only on weekends and public holidays in summer. It quickly became popular, with visitors queueing up at the confectioner’s shop in such large numbers that Kinseiken Daigahara limited production to 300 cakes a day. Other firms in Japan developed variations of the cake. Chef Darren Wong introduced his version to New York’s Smorgasburg outdoor food market in 2016, with its sale, as in Japan, restricted to summer weekends, and the raindrop cake soon became a food fad item much in demand. Versions also turned up in restaurants in Australia and Hong Kong.
The raindrop cake is at first glance simple to make, with only two ingredients: water and agar, a polymer derived from red algae that is somewhat firmer than animal-derived gelatin. (Some recipes add sugar to the mix.) The agar is placed in a saucepan and stirred, with water added slowly to avoid lumping, and then brought to a boil. The saucepan is set in cold water so that the agar cools quickly, and the resulting gel is set in a spherical mold and refrigerated for an hour. It is usually served with kinako (roasted soy powder) and kuromitsu (black sugar syrup), the latter of which has a molasses-like quality that lends the cake temporary solidity. Even with the addition of the syrup, though, a raindrop cake holds its form for only about half an hour outside a refrigerator.
The raindrop cake, which has been described as a ball of water, is vegan and nearly free of calories, and it lends itself well to experimentation by home cooks with, for instance, the introduction of rosewater or fruit juice to the mix.