Berliner Kartoffelsuppe

Berliner Kartoffelsuppe belongs to the cold months and to the city table: weeknight food, cheap food, and still worth doing properly. Berlin and Brandenburg make it from the winter larder, potatoes, carrots, celery, leek, smoked bacon, and marjoram. In the north it can stay clearer and sharper, with more leek and smoked pork. In the south, an Erdäpfelsuppe may be smoother, creamier, and touched with caraway. Im Norden anders, im Süden anders. This is the Berlin pot.

The technique is simple and it decides the soup. Cook floury potatoes until they begin to break at the edges, then mash only part of them in the broth. The broken potato gives body because its starch thickens the liquid; leave every cube whole and you've made broth with vegetables, puree everything and you've made paste. Half crushed, half left standing. That's the spoonful you want.

Start the bacon slowly so the fat comes out before the vegetables go in. If you scorch the onion early, the whole pot tastes bitter under the marjoram. The rind goes in too if you've got it, then comes out at the end, because Weggeworfen wird nichts, nothing gets thrown away when it can give flavour first.

Finish with sausage if you like, Bockwurst or Wiener warmed gently in the soup, not boiled to rubber. Taste at the end, after the bacon and sausage have spoken. Würzen, Fett, Salz zum Schluss. Better still, cook it today and eat it tomorrow. Das braucht seine Zeit, even on a weeknight.