Which Fermented Foods Contain Live Cultures? Pasteurization, Heat Treatment and Label Wording

Which fermented foods can still contain live microbes, how heat treatment and pasteurization change that, and what label wording such as live and active cultures means in the sources.

Content last updated October 22, 2026. This page has not been medically reviewed.

Quick answer

Fermented does not always mean live. Whether a fermented food still has living microbes depends on what happens after fermentation, especially heat treatment or pasteurization. An expert panel from the International Scientific Association for Probiotics and Prebiotics (ISAPP) said there is no expectation that fermented foods must contain live microorganisms. [1] This page is information only, not medical advice.

How the sources sort common foods

ISAPP's table places foods in groups by whether live microorganisms are present in the final product. The table below repeats that sorting. It describes typical products, so an individual product can differ and the label matters.

Group in the ISAPP table	Examples listed	Source
Live microorganisms present	Yoghurt, sour cream, kefir, most cheeses, miso, natto, tempeh, non-heated fermented vegetables. [1]	ISAPP panel, 2021
Live microorganisms absent	Bread, and heat-treated or pasteurized fermented vegetables, sausage, soy sauce, vinegar and some kombuchas. [1]	ISAPP panel, 2021

The sources we read do not say how many store-bought sauerkraut, kimchi or kombucha products are heated, so the label is the only guide.

Sauerkraut and other fermented vegetables

The ISAPP table separates non-heated fermented vegetables from heat-treated or pasteurized ones. [1] For home canning, a USDA-based guide describes bringing sauerkraut and liquid slowly to a boil in the hot-pack method. [3] The same guide says fully fermented kraut may instead be kept tightly covered in the refrigerator for several months. [3] We read no source that measures live counts in either version, so we do not state a count. See sauerkraut and kimchi.

Does pasteurizing change what a study found?

One randomized, double-blinded study gave 34 Norwegian adults with irritable bowel syndrome either pasteurized or unpasteurized sauerkraut. [4] The change in symptoms did not differ between the two groups. [4] The authors said the effect could be attributed more to potential prebiotics in the sauerkraut than to the viable bacteria, and noted the study was underpowered. [4]

Both groups received sauerkraut, so this study cannot show whether sauerkraut beat no sauerkraut. Evidence label: limited (one small pilot study). It does not show that live cultures are unnecessary in general.

Label wording

ISAPP suggested wording for products, with the footnote "as allowed by local or regional regulations": a food without live microorganisms can be labelled "foods made by fermentation", and one with them "contains live and active cultures". [1] A label of "contains probiotics" should be used only when the strains are defined to the strain level. [1] ISAPP also notes that some manufacturers add microorganisms after a heat treatment. [1]

Proper evidence not found: we searched the FDA yogurt standard, the ISAPP statement and NHS pages for official definitions of "raw", "unpasteurized", "naturally fermented" or "contains probiotics" on sauerkraut, kimchi or kombucha labels. None is described in the sources we read. For label reading in general, see probiotic strains and labels and fermented foods vs probiotic supplements.

Official intake levels

The sources we read do not describe an official recommended intake of live cultures.

Frequently asked questions

Is pasteurized sauerkraut still a probiotic food?

ISAPP lists heat-treated or pasteurized fermented vegetables among foods without live microorganisms. [1] It also says fermented foods should be labelled "contains probiotics" only with strain-level evidence. [1]

What does "live and active cultures" mean on yogurt?

In the US standard it is optional wording, allowed only at a stated minimum count per gram at manufacture. [2]

Does heat-treated yogurt have to say so?

In the US, yogurt treated after culturing must be accompanied by the phrase "does not contain live and active cultures". [2]

Do the live bacteria in fermented foods matter for health?

Unclear. In one small sauerkraut study, symptom change did not differ between pasteurized and unpasteurized groups. [4]

Which fermented foods usually have live cultures?

ISAPP lists yoghurt, kefir, most cheeses, miso, natto, tempeh and non-heated fermented vegetables as examples with live microorganisms. [1]

More details: evidence, limits and cautions

The details behind this page: cautions, limits of the evidence and where sources disagree. Open any note to read it.

Yogurt: a legal standard in the US

In the US, the federal yogurt standard sets out rules that other fermented foods do not have in the sources we read:

The dairy ingredients must be pasteurized or ultra-pasteurized before the culture is added. [2]
The characterizing culture contains the lactic acid-producing bacteria Lactobacillus delbrueckii subsp. bulgaricus and Streptococcus thermophilus. [2]
To extend shelf life, yogurt may be treated after culturing to inactivate viable microorganisms. [2]
If it was treated this way, the name must be accompanied by the phrase "does not contain live and active cultures". [2]
The phrase "contains live and active cultures" is optional. It may go with the name only if the food has at least 10 million colony-forming units (CFU) per gram at manufacture, with a reasonable expectation of 1 million CFU per gram through the assigned shelf life. [2]

These are US rules for yogurt (21 CFR 131.200, as read on the Cornell Legal Information Institute site). ISAPP says yoghurt is the notable exception where, depending on the jurisdiction, specific requirements can exist. [1] In Europe, it notes that health claims on live yoghurt cultures and lactose digestion are approved by the European Food Safety Authority. [1] See yogurt.

Safety and who should ask first

Unpasteurized does not mean safer. The FDA says pregnant women, the elderly and people with weakened immune systems should not eat unpasteurized milk and unpasteurized milk products. [5] The NHS lists unpasteurised milk, cream, yoghurt, butter and ice cream among foods to avoid in pregnancy. [6] Other points (salt, histamine, home fermenting) are in fermented foods safety. Children, kidney or liver disease, medicine interactions and surgery are not covered by the sources used here; ask a clinician or pharmacist, and see probiotic safety.

References

Marco ML et al. The International Scientific Association for Probiotics and Prebiotics (ISAPP) consensus statement on fermented foods. Nat Rev Gastroenterol Hepatol 2021;18:196-208 (PMID 33398112). Read 2026-10-23.
US Code of Federal Regulations, Title 21, section 131.200, Yogurt, as published by the Cornell Legal Information Institute. 21 CFR 131.200. Read 2026-10-23.
National Center for Home Food Preservation (University of Georgia; adapted from USDA Complete Guide to Home Canning, 2015). Sauerkraut. Read 2026-10-23.
Nielsen ES et al. Lacto-fermented sauerkraut improves symptoms in IBS patients independent of product pasteurisation: a pilot study. Food Funct 2018 (PMID 30256365). Read 2026-10-23.
US Food and Drug Administration. Listeria (Listeriosis). Content current as of 16 January 2025. Read 2026-10-23.
NHS (UK). Foods to avoid in pregnancy. Page last reviewed 15 June 2026. Read 2026-10-23.

Education, not medical advice. This page is for general information. It does not diagnose or treat any condition and is not a substitute for care from a qualified health professional. Natural does not automatically mean safe. Ask a clinician or pharmacist before changing your care, especially if you take medication, are pregnant or breastfeeding, or have a health condition.