Not-so-sweet Tsubu-an: Japanese Azuki Bean Paste (revised and updated)

Sweet azuki beans

(Update posted January 2011:) I've updated this recipe for classic tsubu-an or "chunky" style sweet azuki bean paste, originally posted back in June 2006, once again. In March 2010 I added instructions for making it with a pressure cooker - the way I've been making tsubu-an for the last couple of years. Since this was originally posted, I've received a number of comments from people who had trouble with their beans getting soft enough. After some experimentation, I've found that if the beans are fresh you can just add the sugar while cooking without much trouble, but if the beans are a bit old - which is the case more often than not unfortunately - you may run into problems. So, in this latest edit, I've revised the instructions so that people having problems with the (possibly old) beans getting soft enough, will have more success.

A lot of Japanese sweets are based on beans that are cooked with a ton of sugar to a paste-like consistency. Red azuki (adzuki) beans are the most popular kind of beans to use in sweets, and sweet azuki bean paste is called an (餡) or azuki-an (小豆あん).

There are many kinds of azuki-an, but the two most commonly used types are koshi-an, and tsubu-an. Koshi-an is an a smooth paste made only from the inside parts of the bean combined with sugar. Tsubu-an (粒あん) is more rustic - the whole azuki beans are cooked until soft, then combined with sugar or sugar syrup; the beans are partially crushed or left whole. (Partially crushed an is also called tsubushi-an (つぶしあん) sometimes. Tsubu-an and Tsubushi-an may sound very similar, but they mean two different things - Tsubu-an means 'whole-bean' an, and Tsubushi-an means 'crushed' an.) (A third type of an that is often seen in commercial sweets, though rarely made at home, is ogura-an (小倉あん), which is koshi-an combined with whole, large "Dainagon" azuki beans cooked in sugar syrup.)

My late oba-chan (grandmother) used to make ohagi and botamochi with homemade tsubu-an every spring and fall. I hated commercial an as a child since it was usually sickly sweet, but I loved oba-chan's tsubu-an; it was not too sweet and even slightly salty.

This not-too-sweet tsubu-an is a good filling for steamed buns; these are called an-man. (I still don't like anman myself for some reason though.) It's also used for dorayaki, which is basically just two small American-style pancakes sandwiched together with a dollop of tsubu-an in the middle. Other Japanese foods that use tsubu-an include anpan (a sweetish bun) and taiyaki (a fish-shaped waffle with an in the middle) My favorite way to eat it though is just as-is, at room temperature. I even add a bit more salt to it, because I love that sweet-salty combination of tastes. (See the links at the bottom of this page for recipes on Just Hungry that use tsubu-an.)

Recipe: Tsubu-an (or Tsubushi-an)

  • 2 cups washed azuki beans
  • 3/4 to 1 cup sugar
  • 1/2 tsp sea salt

Conventional method

Soak the beans in cold water to cover for 24 hours.

Drain the beans and put them in a pot with water to cover. Bring the water to a boil, boil for a minute then drain the beans. Rinse the beans briefly under cold running water and drain again. Put the beans back in the pot with fresh cold water, bring to a boil, then drain and rinse again. This twice-boiling gets rid of much of the surface impurities and makes the an taste cleaner.

Put the beans back in the rinsed pot, and add enough water so that it comes up to about 2cm/1 inch above the beans. Bring to a boil, then lower the heat to a low simmer. Add water if it boils away. Skim off any scum on the surface. Cook until the beans are completely cooked and falling apart. Drain the beans, reserving the cooking liquid.

Put the pot of beans back on medium-low heat. Add the sugar and salt in 3-4 batches, while stirring with a wooden spoon or spatula to distribute the sugar and salt evenly. When the sugar melts, it will exude moisture, but if it seems a bit too dry or sticking to the pot, add a little of the reserved cooking liquid back in. Continue cooking while stirring occasiontaly, until the sugar is completely melted and absorbed into the beans. This step takes 10-15 minutes.

At this point the beans should be soft enough to mash easily with the side of your spatula. You can also use a potato masher. Turn out onto a plate to let cool.

Pressure cooker method

With a pressure cooker, there's no need to presoak the beans, though you can if you want to.

Put the beans in a pressure cooker, with enough water to come up to at least 1 inch / 2 cm above the surface of the beans. Bring to a boil, boil for a minute, then drain the beans. Put the beans back in the pot with fresh cold water, bring to a boil and drain again. This twice-boiling gets rid of much of the surface impurities and makes the an taste cleaner - particularly important when using a pressure cooker, since you can't open the lid while the beans are cooking!

Wash out the pressure cooker pot and add the beans back, with enough fresh cold water to come up to at least 1 inch / 2 cm above the surface of the beans. Put the lid on and lock. Bring the pressure cooker up to pressure over high heat, following the manufacturer's instructions, then lower the heat and cook for 20 to 25 minutes (15 minutes if the beans were pre-soaked). Let rest for 10 minutes, then remove the pressure so that you can open the lid safely. At the point the beans should be completely soft and falling apart. Drain off the cooking liquid.

Put the pot of beans back on medium-low heat. Add the sugar and salt in 3-4 batches, while stirring with a wooden spoon or spatula to distribute the sugar and salt evenly. When the sugar melts, it will exude moisture, but if it seems a bit too dry or sticking to the pot, add a little of the reserved cooking liquid back in. Continue cooking while stirring occasiontaly, until the sugar is completely melted and absorbed into the beans. This step takes 10-15 minutes.

At this point the beans should be soft enough to mash easily with the side of your spatula. You can also use a potato mssher. Turn out onto a plate to let cool.

Both methods - storing tsubu-an

Tsubu-an will keep in the refrigerator, well covered, for up to 3-4 days. It doesn't freeze that well - the texture turns rather grainy.

Notes and more links

  • See my article about Japanese red rice and beans for more about azuki beans.
  • I hate the word "adzuki". It sounds like some made-up word, probably coined by an non-Japanese speaker, and is phonetically incorrect. Let's stick with "azuki"!
  • You can find azuki beans at South Asian/Indian grocery stores, as well as Chinese grocery stores - though the ones you can get from Japanese grocery stores are of higher quality (and more expensive). You'll need to know what you are looking for though, since they are not marked as 'azuki/adzuki' but just as 'red beans'.
  • I used to have a paragraph here about old beans, but I believe that the revised method here should work even if you do have not-quite fresh beans. However, if you can please do try to find fresh beans, azuki or any other type - they are so much better!
  • While an may seem rather healthier than western style sweets since it's, well, beans, do remember that it also has tons of sugar! (See Wagashi are not some sort of Magic Japanese diet food)

Recipes on Just Hungry that use tsubu-an:

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