Roughly chop the shallots. Dice the potatoes into small cubes so they cook evenly. Drain the sauerkraut well, but save the liquid, then chop it finely.

Build the base

In a large pot, melt the butter over medium heat. Add the shallots and cook for about 5 minutes, until soft and translucent but not browned.

Add the potatoes

Stir in the diced potatoes and cook for another 3 minutes, letting them lightly coat in butter and absorb flavor.

Simmer gently

Pour in the vegetable broth and cream. Bring to a gentle boil, then reduce the heat to very low. Simmer for 20–30 minutes, until the potatoes are fully tender.

Add the sauerkraut

Stir in the chopped sauerkraut. Continue cooking on very low heat for 1 to 1½ hours, until the cabbage begins to break down and soften completely. This slow step is key to a smooth, elegant flavor.

Blend until silky

Blend the soup until completely smooth using an immersion blender or a countertop blender.

Season thoughtfully

Add about 1 teaspoon soy sauce and black pepper. Taste before adding salt. If the soup needs more acidity, slowly add reserved sauerkraut juice, about ¼ to ½ cup, until the flavor feels balanced and alive.