Kimchi vs sauerkraut: how they compare on evidence and safety

Both are vegetables fermented by lactic acid bacteria. Salt draws juice out of the cabbage to make a brineNchfp, and the bacteria turn the vegetable's sugars into acid, which preserves the food and gives it its sour flavor. Sauerkraut and kimchi are among the oldest fermented foods, valued first for shelf life, safety and taste Marco 2017.

Sauerkraut is the plain version: shredded cabbage and salt. The tested home method from the National Center for Home Food Preservation uses 3 tablespoons of canning or pickling salt per 5 pounds of cabbage and ferments it at 70 to 75°F for about 3 to 4 weeks Nchfp. Kimchi usually starts with napa cabbage or radish and adds chili, garlic, ginger, scallions and, in many recipes, fish sauce or salted seafood, so it is spicier, more complex and not always vegetarian.

Kimchi. A 2025 systematic review found five intervention studies with 205 participants and four prospective cohort studies with 42,455 participants. Pooling the intervention studies, kimchi lowered fasting blood glucose by about 1.9 mg/dL. After dropping studies that made the results inconsistent, it also found lower triglycerides and blood pressure. The cohort studies linked higher kimchi intake with lower rates of cancer and metabolic syndrome. The authors said the small number of studies means the findings should be read cautiously Ahn 2025. Cohort studies show associations, not cause.

Sauerkraut. In a six-week Norwegian pilot trial, 34 people with irritable bowel syndrome ate either pasteurized or unpasteurized sauerkraut daily. Symptom scores improved in both groups, with no difference between them, and gut bacteria changed. Bacteria from the sauerkraut showed up in stool more often in the unpasteurized group. The authors noted the study was underpowered, and with no placebo group the improvement could be partly expectation Nielsen 2018.

Both. A Stanford trial of a high-fermented-food diet raised gut microbe diversity and lowered inflammatory markers in healthy adults over 17 weeks, but the diet mixed many fermented foods and had 18 people per group Wastyk 2021. These findings are why our fermented foods page grades gut microbiome effects as limited.

Salt is part of both recipes and cannot be left out of a safe ferment. In Korea's national nutrition survey for 2013 to 2017, kimchi was one of the top three dish groups for sodium, supplying roughly 490 to 540 mg a day, and the authors named eating less soup and kimchi as an effective way to cut sodium Jeong 2021. Sauerkraut is salted at a fixed ratio for safety Nchfp.

If you watch your sodium, use either as a condiment: a forkful or two alongside a meal rather than a bowl, and leave the brine in the jar. Check the Nutrition Facts label on store-bought jars, since brands vary.

For live microbes, buy refrigerated, unpasteurized jars; shelf-stable canned sauerkraut has been heated, since canning means bringing it to a boil or processing it in a canner Nchfp. At home, use canning or pickling salt and measure carefully, because the proportion of salt to vegetable affects safety as well as flavor Nchfp. Fully fermented kraut keeps, tightly covered in the refrigerator, for several months Nchfp. Our sauerkraut and kimchi recipes walk through the steps, and the fermentation page covers equipment.

Jarred kimchi is easy to find in Asian groceries and most supermarkets; online, iHerb lists some.