About Adzuki Beans
The adzuki bean, also known as the small red bean, originated in China and is a common feature in the cuisine of East Asian countries such as China, Japan and Korea. Although they are sometimes simply referred to as red beans, they should not be confused with kidney beans, which are twice the size and shaped like kidneys.
From a nutritional standpoint, the adzuki bean is credited as “the red pearl in grain” because it is a legume with a very high starch content. To put it in perspective, the adzuki bean is 58% carbohydrates and 20% protein; in comparison, the soybean is 30% carbohydrates and 36% protein. Since adzuki beans have a sweeter taste than most beans, they are often used in desserts as opposed to savoury dishes.
Macrobiotic cuisine considers adzuki beans to be the most warming (yang) of all beans – good for imparting strength and helping people to keep warm in cool weather. In Traditional Chinese Medicine philosophy, adzuki beans are said to support kidney, bladder and reproductive functions. In Ayurvedic philosophy, legumes including adzuki beans tend to have a sweet and astringent taste (rasa). Legumes, with the exception of mung beans, are not traditionally part of a yogic diet as they are considered rajasic; they stimulate the body, mind and senses. Nevertheless, legumes like adzuki beans can have a use in the diet, for example, to break up stagnant energy. Most legumes have a pungent post-digestive effect (vipaka).
How to Cook Adzuki Beans and Make Red Bean Paste
From a culinary standpoint, the adzuki bean is considered among the easiest to digest and they cook faster than most beans (approximately 1-1 1/2 hours). They do not require pre-soaking, although there is no harm in doing so. For creamy, evenly cooked beans, the trick is to cook them under a steady, gentle heat, and never a full boil. It is also important to throw off the first batch of cooking water to remove any mustiness and give a clean flavour at the end. You could also add a small piece of kombu to tenderise the beans and impart minerals. I have not tried this and so cannot conclude whether it affects the flavour of the cooked beans. So far I cooked the adzuki beans with the intention of using them in desserts, so I left out the kombu.
Red bean paste can be left chunky and textured, or pressed through a screen to get a smooth paste. Once the beans are cooked until tender, you add a sweetener (and optionally, oil), and reduce the mixture to a thick, glossy consistency.
Difference between Japanese and Chinese Red Bean Paste
Japanese red bean paste (anko) is made with adzuki beans and sugar only. It can be textured (tsubuan) or smooth (koshian). Chinese red bean paste is almost always smooth and contains additional oil.
How to use red bean paste
As mentioned earlier, adzuki beans are traditionally used in China, Japan and Korean cuisine, which I will elucidate below.
In Japanese cuisine, anko finds its way into pancakes (taiyaki, obanyaki, dorayaki), buns (anpan), soup with mochi (oshiruko / zenzai), all sorts of dumplings (dango, ohagi, daifuku, manju), icy desserts (kakigori, anmitsu), and glutinous jelly (mizu yokan). Apart from sweets, whole adzuki beans are often cooked together with kabocha pumpkin in a stew (nimono) flavoured with a tinge of soy sauce and sake.
Almost equivalent in nature, Chinese red bean paste finds its way into mooncakes, yeasted pancakes (min jiang kueh / apam balik), steamed buns (豆沙包; dou sha bao), red bean soup (红豆沙; hong dou sha), various dumplings (glutinous rice tang yuan, fried sesame donuts jian dui), icy desserts (chendol, ice kachang), and glutinous jelly (nian gao).
Tips on making adzuki bean brownies
I borrowed the idea of adzuki bean brownies from black bean brownies. I wanted to keep the recipe minimal and have a clean chocolate taste, so the only binder in this brownie is adzuki beans, and a bit of almond butter. The other ingredients you will need are straightforward – cacao powder, cacao butter (for the chocolate flavour), vanilla, salt and baking powder. Once you have prepared the red bean paste (you can make a large batch and store in the freezer), getting your brownie batter together is a one-bowl breeze.
A trick I learnt from making medu vada (urad dal donuts), and which be applied to making all baked bean-based products, is to whip the bean batter very vigorously to make it light and fluffy. Bean-based products can be very dense especially when made as a paste, so it definitely helps to incorporate as much air as you can into the batter, in addition to the help of baking powder.
I tested this recipe three times. The first is a non-baked brownie which turned out like frozen fudge or chocolate potong ice cream. The second time I baked a batter that was sweetened with coconut sugar. It came out almost like a classic brownie with a crackly top and caramelised sugar mixed with cacao. However it veered on being too crumbly. The third time I baked a batter that was sweetened with dates. It came out chewy and fudgey, almost way too fudgey, and I missed the crisp exterior of the former. Perhaps a balance would be achieved if using half each of the two types of sweeteners, but I have yet to try this out.
For more delicious brownie recipes, check out my:
Red Bean Paste (Japanese & Chinese Style) + Adzuki Bean Brownies (Vegan, Grain-Free)
How to make adzuki "red bean" paste with the Japanese and Chinese methods. Japanese red bean paste (anko) is made with adzuki beans and sugar only, and can be textured (tsubuan) or smooth (koshian). Chinese red bean paste is almost always smooth and contains additional oil. The recipe below provides healthier options for the sweetener and oil.
How to make easy one-bowl adzuki bean brownies (vegan, grain-free, date-sweetened) with prepared red bean paste.
Japanese Style Red Bean Paste (Anko)
- 200 g (1 cup) dried adzuki beans
- 3.5 L filtered water (divided into 1.2 L + 1.5 L + 0.25x3)
- 100-133 g (+/- 1 cup) coconut sugar OR
- 266 g (+/- 25 no) pitted Medjool dates, blended to a paste
Chinese Style Red Bean Paste
- 1 batch Japanese Style Red Bean Paste (Anko) (recipe above)
- 70 g (7 tbsp) coconut oil
Adzuki Bean Brownies
- 1/2 batch Chinese Style Red Bean Paste, smooth (recipe above; preferably date-sweetened - see Notes)
- 48 g (3 tbsp) activated almond butter
- 16 g (3 tbsp) cacao powder
- 15 g (1 1/2 tbsp) cacao butter, melted
- 1 1/2 tsp vanilla extract
- 1/8 tsp Himalayan salt
- 1/2 tsp baking powder
Japanese Style Red Bean Paste (Anko)
Wash the beans and remove any stones and debris. Place the drained beans in a large pot with 1.2 L water and bring to a boil over medium heat. Reduce the heat to maintain a steady and gentle simmer. Cook the beans for 8 minutes, or until the water turns wine red. Drain the beans and discard the first batch of cooking liquid. This action is said to "remove astringency" (shibumi kiri).
Rinse the pot and remove any scum that might be clinging onto the sides.
Return the beans to the clean pot, add 1.5 L water, and bring to a boil over medium heat. Reduce the heat to maintain a steady and gentle simmer. Cook the beans for 30 minutes, or until the water barely covers the beans. Skim away any scum and loose skins occasionally.
Add 0.25 L cold "surprise water" (bikkuri mizu) and continue to cook over medium heat for 15-20 minutes. Repeat this "surprise water" treatment about 3 times, or until the beans are tender and collapse when pinched between your fingers.
For Tsubuan (textured anko). Add the sweetener of your choice (coconut sugar or date paste) and simmer for another 10-20 minutes. The final bean paste should be slightly chunky, look glossy, smell nutty and aromatic, and be thick enough to coat the back of a spatula. Towards the end of cooking, stir constantly to prevent scorching.
For Koshian (smooth anko). After the last addition of "surprise water," press the beans through a fine-mesh sieve or nut milk bag into a bowl. It is easier to do it when it the beans are at the more watery stage. Discard the fibrous solids and return the bean paste to the pot. Add the sweetener of your choice (coconut sugar or date paste) and simmer for another 10-20 minutes. The final bean paste should be smooth and creamy, look glossy, smell nutty and aromatic, and be thick enough to coat the back of a spatula. Towards the end of cooking, stir constantly to prevent scorching.
Remove the pot from the heat and set aside to cool.
Transfer the cooled paste to an airtight container. Store in the refrigerator for up to 5 days, or in the freezer for up to one month.
Chinese Style Red Bean Paste
Follow the same steps above, but add the coconut oil along with the sweetener and proceed with reducing to a paste.
Adzuki Bean Brownies
Preheat the oven to 175°C (350°F) .
In a large mixing bowl, combine all the ingredients except the baking powder.
Using a hand whisk, whip the bean batter vigorously for 5 minutes like beating an egg. This helps to make the batter light and fluffy, a trick I learnt from making medu vada (urad dal donuts) and can be applied to making all baked bean-based products.
Add the baking powder into the whipped batter and gently fold-in to combine. The final batter should be of a thick consistency; you should be able to hold it between your fingers, and it should maintain the shape you give it.
Transfer the batter into a greased baking pan or mold. Use an angled spatula to spread the batter in an even layer, being sure to work it into the corners of the pan. Bake for 35-40 minutes, or until a knife inserted in the centre comes out mostly clean. Let the brownies cool completely before cutting into 9 squares for serving. Store the brownies in an airtight container in the freezer for up to 4 weeks.
How the choice of sweetener affects the brownie's texture
Dates give chewy, fudgy brownies, while coconut sugar (dry sugar) gives crispy, crackly brownies. Depending on what type of brownie person you are, use dates or sugar accordingly.