Red Bean Paste (あんこ – Anko)
Anko forms the basis of most traditional Japanese pastry, so having a good sweet Red Bean Paste recipe is a must if you want to delve into the world of wagashi. The traditional process involves hours of soaking, simmering, and stirring to make. Growing up, it was always a treat when my mom made a batch, but I remember one time when she almost burned the house down after leaving a pot of red beans unattended.
The good news is that I’ve spent the past few years working on a simplified recipe for making Anko. The process I’ve developed takes advantage of some modern science to significantly reduce the time and effort required to make a delicious Red Bean Paste with a creamy texture that rivals the Anko made in the best wagashi shops in Japan.
Why This Recipe Works?
- Using a pressure cooker to cook the beans physically speeds up the cooking time for the beans by raising the boiling temperature of the water.
- Adding salt and baking soda to the boiling liquid chemically speeds up the cooking time by weakening and breaking down the pectin in the beans. This makes them soften faster.
- Usually, the sugar is added to the cooked beans, which must then be stirred constantly like risotto until the Anko has thickened. Separating the boiling liquid from the beans and reducing it to a syrup with the sugar speeds up the time to finish the Red Bean Paste and cuts the time you need to stir the beans.
- The syrup-making process also has the added benefit of making the finished Anko very glossy, a sign of high-quality Red Bean Paste.
Ingredients for Red Bean Paste
- Adzuki beans – Adzuki beans, also sometimes spelled Azuki beans (pronounced ah-zu-ki) are a legume that has been cultivated in East Asia for thousands of years. Although there are a few exceptions (the most notable being sekihan), Adzuki beans are almost always sweetened and used to make traditional Japanese sweets. When buying adzuki, look for beans that are vibrant maroon in color with shiny taut skin. The beans should also be relatively uniform in size and color. Different sized beans won’t cook in the same amount of time, and different colors usually indicate the presence of bad beans in the mix.
- Salt – Salt plays two roles here. The first is that the sodium ions switch places with the calcium ions in the pectin in the beans. This weakens the pectin that holds the skins together, making them soften faster. The second purpose of the salt is to enhance the umami taste in the beans. Personally, I don’t like my Red Bean Paste to taste salty, so I use only a tiny amount, but you can increase this to 1/4 teaspoon or more to make it saltier.
- Baking soda – a small amount of baking soda raises the pH of the boiling liquid, breaking down the pectin molecules in the beans. This significantly speeds up the time required to soften the beans.
- Sugar – Sweet Red Bean Paste is usually used with other ingredients to make desserts. Because the Anko needs to sweeten the other ingredients, it is generally made quite sweet. I don’t like my Red Bean Paste cloyingly sweet, so I use a ratio of 1:0.9 Adzuki beans to sugar, but if you want sweeter Anko, you can increase this ratio to as much as 1:1.3. Also, I like using evaporated cane sugar for this because it has a slight caramel flavor.
How to Make Red Bean Paste Quickly
The first thing you want to do is wash the Adzuki beans. I usually wash them in a strainer, but you can also do this with a bowl. If you’re using high-quality beans, you shouldn’t have an issue with bad beans or foreign debris, but you may want to give them a once over to ensure you don’t have any red beans with holes in them or pebbles or twigs.
Add the washed red beans to a pressure cooker and add the water, baking soda, and salt. Affix the lid, set it to “high,” and bring the cooker up to pressure over high heat. Reduce the heat until you have a constant stream of steam escaping, but it doesn’t sound like a jet about to take off. Set the timer for twenty minutes.
If you’re using an electric pressure cooker like an Instant Pot, you can follow the same times, adapting the processes for your setup.
If you don’t have a pressure cooker, you can simmer the beans in a regular pot, but it could take up to an hour for your beans to soften. You will also likely need to add some water part of the way through the cooking process to keep the beans from burning.
Once the timer is up, cut the heat and let the pressure fall naturally. I usually let it sit for another twenty to thirty minutes. If you are not using a pressure cooker, you can skip this step and proceed once your beans are soft enough to smash between your fingers.
Put a strainer over a frying pan (I recommend using a non-stick pan for this), and drain the cooked red beans. Use a spatula to press on the beans to get as much liquid out as you can, but don’t press so hard that the beans start coming through.
Add the sugar to the bean liquid and turn the heat onto high heat. As the mixture comes to a boil, skim off any scum that floats to the surface. Continue boiling the liquid until it’s about the thickness of maple syrup and has reached a temperature of 230°F (110°C).
Dump the beans into the pan with the syrup and stir the mixture together. Now you want to continue cooking while stirring the beans until it’s thick enough that you can run a spatula across the pan without having the Anko immediately flow back into the path you traced with your spatula.
Let the Red Bean Paste cool to room temperature and then transfer it to a sealed container and refrigerate it overnight. This step is very important as it gives the baking soda time to neutralize while allowing the flavors in the Anko to meld and mature.
Other Japanese Sweets Recipes
Anko (あんこ or 餡こ) is a sweet red bean paste made from Adzuki beans that have been cooked until tender and then sweetened with sugar as it is cooked down into a thick paste. It can be prepared with whole beans remaining for tsubuan (粒あん), or it can be mashed and passed through a sieve to make a smooth paste known as koshian (こしあん).
Anko is a two-syllable name that is pronounced as follows:
an like swan
ko like corner
As long as the sugar you use is vegan-friendly, this Red Bean Paste recipe is vegetarian and vegan.
If you eat the anko right away there will be a slight bitterness to the Anko from the baking soda. To eliminate this, all you need to do is leave the anko in the fridge overnight. This allows the baking soda time to neutralize and you will not be able to taste it the next day.
Tsubu-an literally means “chunky anko” while Koshi-an means “strained anko”. As the names imply, Tsuban leaves the beans intact while Koshian has the beans smashed and pressed through a strainer to achieve a smooth consistency.
Red Bean Paste forms the basis for many types of wagashi (和菓子) or traditional Japanese sweets. For example, rice cakes can be stuffed with Anko to make Daifuku (大福)or various types of mochi such as Kashiwa Mochi, Sakura Mochi, or Kusa Mochi. The sweet Red Bean Paste can also be wrapped around a ball of mochi rice to make Ohagi (お萩) or Botamochi (ぼたもち). The Anko can be pureed and gelled to make Yōkan. It can be turned into a soup to make Oshiruko (おしるこ) or Zenzai (ぜんざい). Stuffed into buns it becomes Anpan (あんパン) stuffed between pancakes it becomes Dorayaki (どら焼き), and stuffed into a fish-shaped pastry it becomes Taiyaki (たい焼き). In the photo below, I’ve added some Anko into a rice wafer to make Monaka (最中), which has a light crispy texture and wonderful toasted rice aroma.
This recipe will make about 750 grams of Red Bean Paste.
- 225 grams adzuki beans
- 4 cups water
- ¼ teaspoon baking soda
- ⅛ teaspoon salt
- 200 grams sugar (~1 US cup)
- Put the Adzuki beans in a strainer and wash them well.
- Add Adzuki beans, water, baking soda, and salt to a pressure cooker and affix the lid.
- Set the pressure to high and bring the cooker up to pressure over high heat.
- Adjust the heat down to maintain a gentle stream of steam escaping from the valve and then set a timer for 20 minutes.
- When the timer goes off, turn off the heat and let the pressure drop naturally for 20-30 minutes.
- When the pressure has dropped, open the lid and then dump the beans into a strainer set over a frying pan (a non-stick pan works best). Press on the red beans with a spatula to get as much liquid out of the beans as possible, but don’t press the beans through the sieve.
- Add the sugar to the bean liquid and bring the mixture to a boil. Skim any scum off that floats to the top and continue boiling the mixture until it is thick and syrupy and has reached a temperature of 230°F (110°C).
- Add the Adzuki beans to the syrup and stir well to combine. Continue cooking the mixture while constantly stirring until the red bean paste has thickened enough that you can run a spatula across the pan without the Anko immediately running back into the path.
- Let the Anko cool to room temperature and transfer it to a container and refrigerate it overnight.