Part 5 on Fermentation: Kimchi versus Sauerkraut
In fermented vegetables, remember that the two components that determine aroma and flavor are the salt concentration and temperature of fermentation. Those are the two main differences between kimchi and sauerkraut.
Sauerkraut, besides being cut more finely, has no other ingredients besides cabbage and brine. It ferments at 64-76 °F/18-24°C for 1 to 6 weeks. Its final salt content is 1-2%, and its final acidity level is 1-1.5%. That higher temperature for sauerkraut results in more lactic acid bacteria, giving it a tangier flavor.
Kimchi is cut into larger chunks and includes plant leaves and stems, too; and hot Korean chili pepper, garlic, and fish sauce are added for flavor. It’s fermented at a lower temperature than sauerkraut at 41-57°F/5-14°C for 1-3 weeks, with a higher salt content in the end (3%) and lower acidity (0.4-0.8%).