Is Sauerkraut Halal?

Sauerkraut is finely shredded white cabbage packed with salt and left to ferment. Bacteria that live on the cabbage turn its sugars into lactic acid, which gives the sour taste and preserves it for months. Cabbage and salt, sometimes with caraway or juniper, are all it needs, so plain sauerkraut is Halal.^[4][1]

Is the fermentation a problem?

No. Sauerkraut ferments to lactic acid, not to alcohol, and it is not an intoxicant; see lactic acid (E270). Korean kimchi is made the same way.

Three things to check

1. Wine in the jar. German shops sell Weinsauerkraut, sauerkraut with wine added, and some jars and tins list white wine. Alsace's choucroute au Riesling or au champagne is cooked in wine. These are not Halal.^[3] Plain sauerkraut lists only cabbage and salt, sometimes with preservatives such as potassium metabisulphite, which are fine.
2. Pork in the pot. Restaurant and home-cooked sauerkraut is often braised with bacon, lard or smoked pork, and choucroute garnie in Alsace is sauerkraut piled with pork sausages, ham and bacon.^[2] Ask how it was cooked.
3. What it is served with. In Germany sauerkraut comes beside pork knuckle, bratwurst and other sausages, often cooked in the same pan.

Buying it

Jars and pouches of plain sauerkraut, raw or pasteurised, are the simplest choice. Read the label for wine, and for "mit Speck" (with bacon) on German packs. Sauerkraut juice and raw "live" sauerkraut are plain fermented cabbage too.

For what it is usually eaten with, see pretzel and schnitzel.