By Nik, founder of 東歐嚴選｜kefir.link and former chef · Updated 2 November 2026
Kabocha’s sweet, starchy flesh blends with soy milk into a thick, velvety soup, and soy kefir adds a gentle tang. Pumpkin potage belongs to yoshoku, Japan’s Western-style cooking, and is a modern favourite with toast at breakfast. The soup needs no cream, and shio-koji gives it a rounded, savoury depth.
A breakfast soup, hot or cold
In Japan, a thick pumpkin potage is often eaten with toast in the morning, and a bagel works just as well. It is not only a winter dish: a soy-milk version is just as good served cold on a summer morning. Fresh or frozen kabocha both work. If the soup is too thick, a little water loosens it, and without a blender you can mash cooked pumpkin and stir it smooth by hand.
Stop the soy milk short of a boil
Soy milk on its own only forms a skin when it boils, but heat together with salt and acid makes its protein clump, much as nigari sets soy milk into tofu. This soup carries both, in the shio-koji and the kefir, so a hard boil can turn it grainy. Unsweetened soy milk with a high soy content separates more easily than lighter soy milk. That is why the soup is warmed over low heat and taken off just before it boils.
What shio-koji brings
Shio-koji is a seasoning made from rice koji and salt, and it gives the soup sweetness and savoury depth rather than plain saltiness. Heat stops shio-koji from tenderising meat or fish, but its sweetness and savoury flavour stay in a hot soup. If you have no shio-koji, a little salt can season the soup instead.
Pumpkin soy-kefir soup
Ingredients
- 300 g kabocha pumpkin Weigh the flesh after peeling and removing the seeds and stringy centre.
- 400 ml unsweetened soy milk Use plain, ready-to-drink soy milk.
- 100 ml plain soy kefir Plain and unsweetened.
- 1 tsp vegetable bouillon powder Add the powder directly; no need to dissolve it in water.
- 1 tbsp shio-koji
- dried parsley For garnish, to taste.
You will need
- Microwave
- Microwave-safe bowl and microwave-safe food wrap
- Blender
- Saucepan and spatula
- Food thermometer
Instructions
- Peel the pumpkin and remove the seeds and stringy centre, then weigh the flesh and cut it into bite-sized pieces.
- Microwave the pumpkin in a microwave-safe bowl, loosely covered with microwave-safe food wrap, at 500 W for about 10 minutes, until the flesh is soft.
- Let the pumpkin cool until it is no longer hot before transferring it to the blender.
- Blend the pumpkin and soy milk into a smooth purée.
- Combine the pumpkin purée, soy kefir, shio-koji and vegetable bouillon powder in a saucepan.
- Warm over low heat, stirring constantly, until steaming and about 80°C (176°F), then turn off the heat before the soup boils.
- Serve the soup in bowls with a sprinkling of dried parsley.
Comments
No comments yet.
Comments could not be loaded.
Join the discussion
or