Azuki (adzuki) beans.
Anko is a sweet paste, made from these small Asian beans. Anko is one of the most common ingredients for making Japanese sweets, so this is a basic.
Azuki beans. Sugar, syrup or any sweetener you like.
Other types of beans can be prepared the same way. White beans (similar to “Navy beans”) are often used to make the white “an”.
I was not too happy with the color of my photos… it varies indeed, it’s nicer in reality than on my shots. What matters is the texture, so I covered with fancy filters.
MAKING ANKO (tsubuan and koshian)
Rinse. Cover with 4 volumes of water. Soak one night (in the fridge in Summer).
Drain (optional, you can keep the soaking water, final color may differ). Transfer into a pasta pot with plenty of water, bring to boil. Pass to medium heat. Take away the white foam. Cover and cook (medium heat) until beans are soft. Depending on quantity that takes me 40 min to 1 hour. Drain.
Rem : You can cook them in a steam-cooker if you have a functional one, it’s faster. You can use a crock-pot, but boiling the beans about 10 minutes is necessary to eliminate toxic substance, so if your crock-pot cannot boil, start in a pot and transfer after taking away the foam.
Paste in a mortar (or with a fork).
This is tsubuan (chunky bean paste). In Kansai, this is the favorite texture.
Make it finer this way :
This is koshian (fine bean paste), it’s the prefered “anko” in Kanto area. Well, both types are available everywhere in Japan.
Sweetening (easy way) :
Add syrup to either tsubuan or koshian. I use already prepared kuro mitsu, black sugar syrup. You can make a syrup with sugar and water. Make it at your taste. You can freeze the paste.
Rem : In some recipes, you add lots of sugar (same weight as beans) and simmer it with the beans before pasting. You obtain a “azuki jam”. You can buy it already made. It can be stored without freezing. The inconvenient is it’s much sweeter.
Koshian (fine paste), prepared as mizu-yokan. This time, the color is more chocolaty, that depends on the beans. I have had redder ones, but these brown ones are particularly taste.