White Bean Paste or Shiroan is commonly used as a filling for wagashi (Japanese confectionery) such as mochi and manju. The paste has a milder bean taste, so it makes a great alternative to red bean paste (anko or an)!
In a large bowl, add the lima beans and rinse them under running water. Then soak them in plenty of water overnight (8 to 12 hours; require longer hours in winter).
Add the beans in the pot and pour cold water just enough to cover the beans. To properly cook the beans, you will use just enough water and don’t let the beans move around in the water.
Bring it to a boil on medium heat. Let it boil for 2 minutes while foam starts to appear.
Cover with a lid (slightly ajar and let simmer on low heat until beans become tender, about 1.5 to 2 hours.
Once in a while check the beans and skim off the foam on the surface. This helps to make the white paste even whiter. Add a bit more water if the water is not covering the beans. Make sure the amount of water is just enough to cover the beans.
Drain the liquid. You may want to save a little bit of cooking liquid for the next step.
Transfer a small portion of drained beans to your fine-meshed strainer (this tool is also a flour sifter) over a large plate. Press the beans through the strainer using a wooden spatula. You will get a finer and smoother paste built up under the sieve/over the plate. If it’s too dry, put a tiny bit of cooking liquid on the beans before pressing. Alternatively, you can use a food processor to mash the beans. Add a little bit of cooking liquid if necessary.
Turn on the heat to medium low heat and let the sugar dissolve. The paste will become liquidy.
Then let the moisture evaporate from the mixture on medium low heat until it becomes a smooth mold-able paste, roughly 15-20 minutes. Keep an eye on the paste all the time to make sure it doesn't burn. When you can draw a line on the bottom of the pan, it’s done. The paste will continue to evaporate as it cools down, remove from the heat and pot immediately.
Transfer the white bean paste to a clean container with a lid. If you’re using it in a few days, refrigerate. Otherwise, divide the paste into a small portion and freeze them for up to 2-3 months.
Lima Beans: If you’re in Japan, you can get one of Shiro Ingen Mame (白いんげん豆) such as Shirohana Mame (白花豆), Ofuku Mame (大福豆), Tebo Mame (手亡豆), or Kintoki Mame (金時豆).Or you can use Shiro Azuki (白小豆). For White Bean Paste, please try finding lima beans (butter beans) or navy beans. If you can't find them, then the last option is Cannellini Beans. I do not recommend substituting with other beans because the taste and texture will be completely off.
Sugar: Please use granulated white sugar, and do not use sugar that has color (such as brown sugar) because you're trying to make WHITE bean paste. If you're going for traditional white bean paste, the sugar amount will be ⅔ to 1 part of sugar by weight to 1 part of beans. If you reduce the amount of sugar significantly, it will not give enough moisture to the paste, which may result in a different texture. Wagashi is meant to be a bit on the sweet side in order to complement the bitter taste of matcha (drink).
Recipe by Namiko Chen of Just One Cookbook. All images and content on this site are copyright protected. Please do not use my images without my permission. If you’d like to share this recipe on your site, please re-write the recipe and link to this post as the original source. Thank you.