KO EN Japanese Appetizer⏱ 45 minEdit history

Goma-dofu (Sesame Tofu Set with Kudzu Starch)

Name: Goma-dofu (Sesame Tofu Set with Kudzu Starch)
Prep time: 10 min
Cook time: 35 min
Total time: 45 min
Yield: 4 servings
Cuisine: Japanese
Ingredients: 100 g White sesame paste (neri-goma); 50 g Kudzu starch; 500 ml Water; 1/4 tsp Salt; a little Wasabi; 1 tbsp Soy sauce

Sesame ground to a paste, whisked with kudzu starch and water, cooked with constant stirring and poured into a mould to set — Japanese temple cooking. It is called tofu and contains no soy and coagulates no protein: what sets it is starch. But it is not quite a starch jelly either. A paste that is roughly half fat sits inside the gel, which is why the same starch sets far more softly here and why so much more of it goes in.

Ingredients

4servings

White sesame paste (neri-goma) · unsweetened; or toast and grind sesame yourself100 g
Kudzu starch · or 45g potato starch — see the tips50 g
Water500 ml
Salt1/4 tsp
To serve
Wasabia little
Soy sauce · let down with a little dashi so it is less salty1 tbsp

Steps

Whisk the kudzu starch into cold water until no lumps are left. Into hot water it seizes on contact and never comes back.
⏲ 3 min
Stir in the sesame paste and salt and work it completely smooth. If it is not smooth now it will not be smooth later.
⏲ 4 min
Set it over medium-low heat and stir without stopping with a wooden spatula, scraping the base and the corners. At around 8-10 minutes it thickens all at once.
⏲ 10 min
Thickening is where the work starts. Drop the heat and stir 20 minutes more. It is ready when the mass pulls after the spatula in one piece and the surface has a sheen.
⏲ 20 min
Pour into a square mould wetted with water and level the top. Knock the mould on the worktop to bring the air bubbles up.
⏲ 2 min
Cool to room temperature, then chill 2 hours to set. Lay cling film onto the surface so it does not dry out.
⏲ 120 min
Cut into squares with a wetted knife. Top with wasabi and spoon a little soy sauce around.

Tips & Variations

Variations

With black sesame: a much darker, greyish block with a far stronger aroma. Often served with salt alone rather than soy sauce.
Where it sits in shojin ryori: in temple cooking without meat or dairy, sesame is what carries fat and richness. That is why a paste this oily goes inside a gel at all — not for the texture but to fill that gap.
With potato starch: easier to find, but softer and less silky in the mouth than kudzu. Drop it to 45g and accept that the particular slipperiness is gone.
Fried (age-goma-dofu): the set block dusted in starch, deep-fried and served in a warm broth. The same idea as agedashi tofu, with a far softer inside.
Its relation to dotori-muk: the setting belongs to the same family and what goes in does not. The tips below are about that difference.

Tips

It is called tofu and does none of the things that make tofu. Douhua draws the line exactly: acid gives you curds and salt ions give you a gel, and then "ladle the curd into a mould and press the water out and it is tofu. Pressing is the only thing that separates them." Goma-dofu has no soy protein to bring together in the first place. No acid, no salt ions, nothing pressed. What sets is starch.
But it is not a muk either, and the difference is the whole dish. Dotori-muk closes that family in its own words: "All three work the same way — one starch, water, and enough cooking." The premise all three share and none of them states is that there is nothing in the gel but starch and water.** Here 100g of a paste that is roughly half fat goes in. Fat coats the starch granules and gets between the chains, so the network never knits as tightly. A muk sets at one part starch to six of water; this barely sets at one to ten, which is why the starch ratio is so much higher.
Which is why the twenty minutes of stirring does not come down. The fat slows the starch taking up water, and all that time it will set on the base and scorch there if the spatula stops. Kaya toast records the same kind of time — "there is no way to shorten the 40-60 minutes of stirring" — the sort you spend working, not waiting.
Kudzu only disperses in cold water. The rule thickening a sauce gives for any starch is not optional here: into hot water the outside of each lump gelatinises and seals the rest in, and that lump will not come out in twenty minutes of stirring.
The finish is a state, not a time. Thickening is not doneness. It is the trap dotori-muk describes when it says the moment it thickens "looks finished" and still needs ten more minutes — and with fat in it this takes longer than that. It is ready when the mass follows the spatula in one piece and the surface has a sheen.
Do not keep it long. A starch gel pushes water back out over time and goes grainy. The day it is made is best, the next day is the limit, and there is no reason to chill it beyond the two hours it needs to set.