ホモテナシ

This is an old revision of the document!

It's a steamed sweet that's wrapped in a skin called すり芋, made from, surprisingly, 山芋. I tried it with とろろ, which you can buy frozen in Yumi Hana, for example.
In to my experience (and according to KM), this is one of the hardest type of 和菓子 to get right. By right, I mean to have a smooth surface without dents and dimples. This has mostly to do with the moisture and elasticity of the すり芋 dough, so it's very specific to the yams (or とろろ, in my case) that you use
Until I can get this right, the steamed 浮島 might be a better idea if I really need something steamed.

Since I use thawed とろろ, let it drip in a sieve to lose some moisture.
Mix grated yam with twice its weight in blitzed sugar bit by bit in a すり鉢. I tried to do it with a normal kitchen tool, but it's no good.
Add this to 40% of its weight in non-glutinous rice flour (上用粉). Let it sit for 15'.

💡 This is not quite the same as 上新粉, so one suggestion is to use a 2:1 mix of 上新粉:白玉粉. This worked well for me.

I used to use 上新粉 to dust the dough and hands because it's so sticky, but potato starch is better here, it makes the surface smoother.
Steam for 8' on baking paper on medium-high heat. The original recipe sprays the sweets with vinegar before steaming, but with potato starch, I don't think that's necessary.
Fan once done to cool quickly.

The original recipe uses 15 gr boiled chestnut and 15 gr smooth あん, but I think it's better with walnuts, and to have it smaller overall (20 gr is fine).
The ratio between the 中あん and the すり芋 should be 10:6 (so 20 gr 中あん, for example, to 12 gr skin).