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Rock sugar, or Koori Zato (氷砂糖) in Japanese, is large sugar crystals that come in jagged rock-shaped of varying sizes. We use them to make Plum Wine and Ume Plum Syrup.
What is Rock Sugar?
Rock sugar or Koori Zato (氷砂糖) is large sugar crystals that come in jagged rock-shaped of varying sizes. Also known as sugar candy, the sugar is made out of a solution of sugar and water through crystallization. It can be made of different types of sugar such as regular white granulated sugar, brown sugar, sugar cane, etc.
Rock sugar is commonly used in East Asian and many other Asian cuisines to sweeten teas, drinks, dessert soups, and liquors. It is the preferred choice of sugar for flavoring teas and soups because it is less sweet than regular white granulated sugar. With a clear taste, the sugar melds beautifully without overwhelming the flavor of the drink.
Rock Sugar in Japanese Cuisine
In Japan, we use white rock sugar/candy to make Plum Wine (Umeshu). Rock sugar takes time to dissolve, which helps to extract the flavors and fragrance from the plums at a slow pace. You can use both Japanese or Chinese brands of rock sugar to make plum wine or syrup. If you’re using Chinese brand, make sure it is the opaque or white-colored type and not the gold-colored rock sugar made from sugar cane.
The best place to find rock sugar is at Japanese or Asian grocery stores. Alternatively, you can also find it available on Amazon.