The Difference: Ogura An vs Tsubu An vs Koshi An
Unlike many countries, Japan has a variety of sweets made with sweetened red bean paste called “Anko (餡子)” or “An (餡)”. Anko actually comes in various different varieties, but many of them are made from the red bean called “Azuki (小豆)”.
The sweet red bean paste is typically used in traditional Japanese confections called “Wagashi (和菓子)”, which include Manju, Daifuku, Dorayaki, and what I introduced in the previous article, Ankoro Mochi.
Anko has different names depending on the form of red beans in it, and the typical examples include Koshi An, Tsubu An, and Ogura An, which actually are the most common types of Anko paste in Japan.
The Difference between Ogura An, Tsubu An, and Koshi An
Nonetheless, many Japanese can’t clearly tell the difference between Tsubu An and Ogura An, because they are very close in appearance. So what is the difference between Tsubu An, Ogura An, and Koshi An?
Koshi An (こしあん)
Koshi An is smooth Azuki red bean paste. The red beans are boiled in water, mashed, strained through cloth, and kneaded up. The skin of Azuki beans is removed. Koshi An is often used interchangeably with Tsubu An. (e.g. Oshiruko and Zenzai)
Tsubu An (つぶあん)
Tsubu An is carefully made grainy so as not to collapse the shape of Azuki red beans as much as possible. The outer skin of beans is not removed. Tsubu An is sometimes called Ogura An, since they are very similar.
Ogura An (小倉あん)
Ogura An is a mix of Koshi An paste and the larger species of Azuki, such as “Dainagon (大納言)”, which is simmered in molasses syrup with its shape retained. The specialty of Nagoya, Ogura Toast is a slice of toast topped with Ogura An.
(Reference Page: Wikipedia 餡 )