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sweet red bean paste recipe (koshian)

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This post is dedicated to sweet red bean paste, or anko as it’s known in Japanese. This glorious substance is a component in many traditional Japanese desserts and yes, you can make it at home. Anko comes in two main varieties: coarse tsubuan and smooth koshian. I have always preferred koshian, but have only recently attempted to make it from scratch. I must warn you, it did take a whole morning. If you want to hear that story, read on. Alternatively, jump to the end for the sweet red bean paste recipe in brief!

red bean paste in haste

‘A whole morning?’ I hear you cry. If you navigated here in the midst of a sweet bean paste emergency, do not fear. Pre-cooked, sweetened adzuki beans are available tinned.

If you live in the UK, a dedicated Asian food shop will be your best chance of finding this product. Alternatively, if the so-called ‘Oriental’ section in your local supermarket is particularly extensive, it may appear there. Shirakiku brand ‘Yude Azuki’ consists simply of whole red beans cooked in a thick syrup. You can spoon this stuff directly onto sundaes or mix it into cakes. You could probably also drain and mash it to make a quick anko. Be warned, however: it’s outrageously sugary; personally, I can’t handle more than a spoonful before my throat starts to burn. In fact, this experience is what first gave me the thought of making my own anko from scratch.

Then, not long ago, I received a sign. It came in the form of a bag of dried adzuki beans. It was twelve months old, unopened and forgotten in the back of my cupboard. Given my occasional carnivore’s guilt around Veganuary, I can only assume I bought it intending to make some sort of penitential stodge. This obviously never materialised. A far more dignified end for the beans, I decided, would be koshian. And so I set about developing my own smooth bean paste recipe. The amount of sugar I settled on may seem conservative, but it results in an an authentic flavour without being aggressively sweet.

the full process

soak and simmer

After their obligatory overnight soak, the beans must be simmered. I replaced the water before starting and again after the pot first came to the boil, as several of my sources insisted. The idea behind this procedure is to reduce the overall amount of scum, although I cannot vouch for its utter necessity or effectiveness! I also threw in an extra cup of cold water every 10-15 minutes or so for the remaining cooking time. I found this was necessary to ensure that the beans remained well covered. Apparently, this is also ‘correct’ practice for regulating the temperature in the pot, as recommended by Elizabeth Andoh and others. I guess this is paramount if you want your beans to cook very gently and emerge smooth and unbroken. Since I was going to remove the skins anyway, this was not a big concern for me.

sieve and squeeze

I removed the skins by passing the cooled beans through a sieve, assisted by the butt of a rolling pin. This took a long time as I had to work in batches. The resultant mash looks like powdery purple snow!

Many recipes call for this puree to be squeezed in a cotton bag to remove excess moisture, but mine was already dry enough that it clung to the bowl and compacted smoothly when pressed.

heat and sweeten

The nerve-wracking part is putting the dryish red bean paste back on the heat and adding the sugar. Once the sugar heats up, however, the paste becomes instantly looser. It’s then just a matter of gently reducing it again to the desired consistency. I have repeatedly read (including in A Simple Art) that side-to-side stirring at this stage makes your koshian glossier and, implicitly, better. I wasn’t sure about this at first, but I think it must be about achieving an even distribution of sugar. It only takes a short time for the paste to re-thicken, and zigzags are simply more efficient than circles when it comes to mixing.

Finally, my sweet red bean paste was finished. The final yield from 250g of dried beans fit in an 870ml (29 oz) container with a little room to spare. This was easily enough for a few bowls of o-shiruko or several dozen dorayaki. But that’s a story for next time!

recipe: smooth sweet red beam paste (koshian)

This smooth red bean paste recipe combines the full flavour of freshly cooked beans with an elegant sweetness. Koshian can be used in various wagashi (traditional Japanese sweets).

ingredients

  • 250 g dried adzuki beans
  • 140 g sugar
  • pinch salt

method

  1. Soak the adzuki beans overnight (minimum 8 hours).
  2. Drain the beans and cover them with fresh water in a large saucepan. Bring to the boil for a few minutes, then replace the water again. Return to the boil and leave on a medium heat for another 45 minutes or until the beans are tender.
  3. Drain the beans well and toss them in the warm pan to force any excess moisture to evaporate. Allow to cool briefly.
  4. Pass the beans through a fine sieve using the end of a rolling pin or similar. (The heavier the tool, the less effort you will have to use). Do this in batches, discarding the empty skins each time.
  5. Check that the paste is not sloppy and retains a smooth imprint when pressed. If it is particularly wet, use a clean cotton bag to squeeze out more moisture. The paste should be solid but not crumbly.
  6. Heat the paste in a saucepan with the sugar and salt. Stir briskly in a zigzag motion to ensure the mixture is well combined. It will become slack as the sugar melts before thickening again.
  7. Remove from the heat as soon as you can draw a clean path on the bottom of the pan with the spoon. Allow to cool before storing in the fridge.