Anko, the sweet Japanese paste.
Anko is a sweet paste made from adzuki beans.
Anko has many uses in Japanese confectionery. It is made from red beans called azuki that are cooked until tender. Once soft, you add pinch of salt and the sugar and you stir it until it thickens.
Tsubuan and Koshian style
Both varieties of anko start from the same recipe, and they only differ in their texture.
Tsubuan (粒あん) is the paste prepared by simply boiling azuki and adding sugar. Therefore, it is the chunky version as the beans remain as a whole.
Meanwhile, koshian (こしあん) is nothing more than anko that’s forced through a strainer to achieve a very smooth and homogeneous texture. This form is the most common for traditional Japanese sweets, known as wagashi.
Here is an image so that you can see, visually, the difference between the two. On the left-hand side we find the anko koshian and on the left-hand side the anko with chunks (tsubuan).
How do I keep it? Can it be frozen?
Making anko at home is a very simple process, but it takes a couple of hours.
So I love to make this recipe with a minimum of 200 grams of azuki. This way, I can store it covered with plastic wrap in the fridge for a week or, my favourite option, in the freezer for up to a month. This allows me to prepare any Japanese sweet without having to make anko from scratch every time.
How to make anko: Tsubuan and Koshian Style
- 200 g adzuki
- 200 g sugar
- 1 pinch salt
- The night before, we soak the adzuki beans in water.
- The next morning, drain the water and rinse the beans.
- In a pot we add the adzuki beans and enough water to cover them.
- Heat the pot over high heat. As soon as the water starts to boil, cover and turn off the heat. Let them stand for 5 minutes.
- Drain the adzuki once more. Pour them back into the pot and, once again, add enough water to cover them.
- Put the pot over high heat. As soon as it starts to boil, lower the heat and leave it simmering for about 1 hour. The water will evaporate so it’s important to keep adding some more.
- After one hour, check the beans. (see note)
- They are ready for the next step when you take a bean between two chopsticks or two fingers and squash it easily.
- At this point, turn up the heat once more. Add a pinch of salt and, stirring constantly, add the sugar.
- The tsubuan-style anko is ready when it thickens and you can see the bottom of the pot for a couple of seconds.
- Once ready, pour the tsubuan on a plate and let it cool - do not leave it in the pot.
- To transform it into koshian style, just pass it through a strainer. If you don't have this kind of strainer, don’t worry you can use a normal one, as I did for more than 3 years. This step allows us to get the smooth and homogeneous texture of the koshian.