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Alcohol in kombucha and kefir

Every drink fermented with yeast has some alcohol. How much studies measure, what raises it and what holds it back, and who shouldn't drink them.

6 min read First steps Reviewed October 26, 2026 41 facts, each with its source

Where the alcohol comes from

Yeasts turn sugar into alcohol and gas, so many ferments contain a little alcohol1. In kombucha, acetic acid bacteria turn part of that alcohol into acid, as long as they have air2. In a sealed bottle they can't, and the alcohol stays. Health Canada lists kombucha, kefir and ginger beer among the non-alcoholic drinks that can contain it3. Tasting like a soft drink doesn't mean it has no alcohol.

For a sense of scale: in the US, a drink with more than 0.5% is regulated as alcoholic4, and in Canada a non-alcoholic drink has to stay at 1.1% or less5.

How much each one has

These are figures from studies and guides, not from your kitchen:

Drink Alcohol measured
Kombucha made with the NCHFP's tested recipe Trace amounts, under 0.016%6
Mountain tea and honey kombucha, in a study, at the end of fermentation 0.49 to 0.75%7
The same, after 30 days sealed in the fridge 1.61 to 1.70%8
Kombucha with a long fermentation, about 30 days Up to 3%9
Jun More than kombucha10, perhaps because of the sugars in honey11
Water kefir, 13 samples from Argentina 0.58 to 2.55%12
Water kefir made with juices 1% or more13: 2.4% for strawberry14 and 5% for pomegranate15
Milk kefir Rarely high16: 0.49% at most in one study, after 21 days at 20 °C (68 °F)17
Ginger beer with a ginger bug 0.64% on day 518
Ginger beer with added yeast 4.32%19

The kombucha figures don't match because it isn't the same kombucha: the tea, the sugar, the days and whether the bottle was sealed all change. The ginger beer study gives alcohol in Gay-Lussac degrees, which are the same as percent by volume.

What raises it and what holds it back

What raises it:

  • Time. The NCHFP says more days of fermentation mean more alcohol20. BCCDC, British Columbia's public health agency, adds that kombucha has to ferment long enough for the alcohol to come down, without getting too acidic21. That's why Fervida sticks to the tested recipe's 7 to 10 days. Milk kefir fermented past 48 hours can go above 1.1%22.
  • More culture. With more water kefir grains, the sugar is used up faster and there's more alcohol23.
  • Sugar added after fermentation, including the sugar in fruit and juice24.
  • A sealed bottle. A kombucha can be bottled under 0.5% and keep fermenting inside25. Some brands reached 3% that way26.
  • Heat, and long storage27.

What holds it back:

  • The fridge28, as soon as the drink is done. It slows things down but doesn't stop them: in the study, sealed kombucha kept gaining alcohol in the fridge. That's why, once flavored, it's drunk within 2 days29.
  • Air. In water kefir, an open jar gives more acetic acid and less alcohol30.
  • No added sugar, and not stretching the recipe's times.

You can't measure it at home

The only reliable way to know how much alcohol a kombucha has is to have it tested in a lab31. The usual methods for beer and wine don't work, or aren't accurate enough, for kombucha32. Even producers don't always keep it in check: in British Columbia, over 30% of the kombuchas tested didn't have their alcohol under control33. That's why Fervida doesn't calculate the alcohol in kombucha, jun, water kefir or ginger beer: the warning is fixed, and that's a house rule.

If you want as little as possible, follow the recipe's times, don't add sugar, move it to the fridge as soon as it's ready and drink it soon.

Who shouldn't drink them

BCCDC asks for labels saying they may contain alcohol and aren't for young children or during pregnancy34. At just 2% alcohol, 200 ml (less than a cup) is enough to pass the toxic level in a 10 kg (22 lb) child35: young children lack the enzyme that breaks down alcohol36. Confusion, overheating and fatigue can be signs of alcohol poisoning, and they easily go unnoticed37. The Public Health Agency of Canada recommends no alcohol during pregnancy38, and the risk reaches breastfed babies too39.

They're also not for anyone who can't have alcohol because of a medication or a health condition, or who is recovering from an addiction40. And drivers should know: some people drink them without realizing they contain alcohol41.

Where every number comes from

Every number in the text leads to its figure: the exact sentence from the official guide it comes from, in its own language.

  1. 1

    Ferments contain some alcohol, because yeasts make it from sugar

    “Fermented foods often contain alcohols in low amounts as a natural by-product of ethanol fermentation, when yeasts convert sugars into ethanol and carbon dioxide.”

    BC Centre for Disease Control, Environmental Health Services · Safety of Fermented Foods, Section 3.12: Kefir, milk and water (December 2024) · read on October 25, 2026

  2. 2

    In kombucha, acetic acid bacteria turn alcohol into acid when there's air

    “The ethanol is then metabolized by acetic acid bacteria in the presence of oxygen to produce acetic acid”

    University of Georgia Cooperative Extension · What’s the Word on Homemade Kombucha? (Circular 1312, 10-apr-2026) · read on October 20, 2026

  3. 3

    Health Canada lists kombucha, kefir and ginger beer among drinks that can contain it

    “Health Canada acknowledges ethanol in non-alcoholic fermented beverages as a concern in kombucha, kefir, and some soft drinks including ginger beer.”

    BC Centre for Disease Control, Environmental Health Services · Safety of Fermented Foods, Section 3.11: Kombucha and Jun (September 2023, updated December 2024) · read on October 25, 2026

  4. 4

    In the US, above 0.5% it's regulated as an alcoholic beverage

    “Food and beverage products that contain greater than 0.5% alcohol are subject to Alcohol Beverage Control Authority (ABC) and/or Alcohol and Tobacco Tax and Trade Bureau (TTB) regulation and taxation.”

    Virginia Cooperative Extension (Virginia Tech) · What do I need to know to sell KOMBUCHA at the farmers market? (FST-297, last reviewed November 2025) · read on October 20, 2026

  5. 5

    In Canada, a non-alcoholic drink has 1.1% or less

    “Federal regulations require 1.1% or less alcohol in non-alcoholic beverages, provincial requirements vary.”

    BC Centre for Disease Control, Environmental Health Services · Safety of Fermented Foods, Section 3.11: Kombucha and Jun (September 2023, updated December 2024) · read on October 25, 2026

  6. 6

    With the tested recipe, trace amounts: less than 0.016%

    “By following our guidelines and recipe, your kombucha may have trace amounts of alcohol (<0.016 % alcohol by volume – ABV).”

    University of Georgia Cooperative Extension (National Center for Home Food Preservation) · Crafting Kombucha at Home: Frequently Asked Questions (2026) · read on October 20, 2026

  7. 7

    0.49 to 0.75% when fermentation ends

    “after fermentation, the ethanol content reached 5.91 ± 0.75, 5.26 ± 0.58, 3.87 ± 0.63 g/L or 0.75 ± 0.10, 0.67 ± 0.07, 0.49 ± 0.08% (v/v)”

    Foods (MDPI), via PubMed Central · Kombucha Fermentation of Olympus Mountain Tea (Sideritis scardica) Sweetened with Thyme Honey (2023) · read on October 25, 2026

  8. 8

    1.61 to 1.70% after 30 days sealed in the fridge

    “After refrigeration for 30 days at 4 °C, ethanol content changed significantly (p < 0.05) in all samples and reached values of 13.41 ± 0.09, 13.10 ± 0.31, 12.84 ± 0.15 g/L or 1.70 ± 0.01, 1.66 ± 0.04, 1.61 ± 0.02% (v/v)”

    Foods (MDPI), via PubMed Central · Kombucha Fermentation of Olympus Mountain Tea (Sideritis scardica) Sweetened with Thyme Honey (2023) · read on October 25, 2026

  9. 9

    Under 1%, but up to 3% with about 30 days of fermentation

    “Typically, the alcohol and acetic acid content of KT are both less than 1%, but each can rise to 3% during a long fermentation (~ 30 days).”

    BC Centre for Disease Control, Environmental Health Services · Food Safety Assessment of Kombucha Tea Recipe and Food Safety Plan (2015, updated 2020) · read on October 20, 2026

  10. 10

    Jun has more alcohol than kombucha

    “The alcohol content of jun is generally higher than kombucha.”

    BC Centre for Disease Control, Environmental Health Services · Safety of Fermented Foods, Section 3.11: Kombucha and Jun (September 2023, updated December 2024) · read on October 25, 2026

  11. 11

    Perhaps because of the sugars in honey

    “This may be due to the differences in the sugars used to culture the two beverages.”

    BC Centre for Disease Control, Environmental Health Services · Safety of Fermented Foods, Section 3.11: Kombucha and Jun (September 2023, updated December 2024) · read on October 25, 2026

  12. 12

    Between 0.58 and 2.55% in 13 samples

    “un contenido de alcohol entre 0,58 y 2,55 (%, v/v)”

    Revista Argentina de Microbiología (Teijeiro et al.; INAL-ANMAT, CONICET) · Análisis de muestras de kéfir de agua para el desarrollo de un marco regulatorio en el Código Alimentario Argentino (2025) · read on October 25, 2026

  13. 13

    Made with juices, 1% or more

    “Of concern, water kefir made from vegetable or fruit juices may contain high levels of alcohol (≥1%).”

    BC Centre for Disease Control, Environmental Health Services · Safety of Fermented Foods, Section 3.12: Kefir, milk and water (December 2024) · read on October 25, 2026

  14. 14

    Strawberry, 2.4%

    “strawberry water kefir: 2.4%”

    BC Centre for Disease Control, Environmental Health Services · Safety of Fermented Foods, Section 3.12: Kefir, milk and water (December 2024) · read on October 25, 2026

  15. 15

    Pomegranate, 5%

    “5% alcohol for pomegranate water kefir”

    BC Centre for Disease Control, Environmental Health Services · Safety of Fermented Foods, Section 3.12: Kefir, milk and water (December 2024) · read on October 25, 2026

  16. 16

    In milk kefir, high alcohol is rare

    “Reports of elevated alcohol in milk kefir, as described above, are rare.”

    BC Centre for Disease Control, Environmental Health Services · Safety of Fermented Foods, Section 3.12: Kefir, milk and water (December 2024) · read on October 25, 2026

  17. 17

    0.49% at most, after 21 days at 68 °F

    “However, the highest alcohol content in cow milk kefir in this study was 0.49% at 21 days at 20oC”

    BC Centre for Disease Control, Environmental Health Services · Safety of Fermented Foods, Section 3.12: Kefir, milk and water (December 2024) · read on October 25, 2026

  18. 18

    With a ginger bug, 0.64% on day 5

    “In the group with ginger bug, the alcohol content was 0.64 ± 0.18 ° GL on the 5th day of fermentation.”

    Revista de Ciências Agroveterinárias (UDESC; Alencar et al., Federal University of Amazonas) · Kinetic and sensory analysis of ginger beer produced by diversified fermentation methods (v.24 n.3, 2025) · read on October 25, 2026

  19. 19

    With added yeast, 4.32%

    “induced fermentation resulted in an alcohol content of 4.32 °GL”

    Revista de Ciências Agroveterinárias (UDESC; Alencar et al., Federal University of Amazonas) · Kinetic and sensory analysis of ginger beer produced by diversified fermentation methods (v.24 n.3, 2025) · read on October 25, 2026

  20. 20

    The NCHFP: more days of fermentation, more alcohol

    “Alcohol content varies according to the fermentation period. Longer fermentation periods will produce more alcohol.”

    University of Georgia Cooperative Extension (National Center for Home Food Preservation) · Crafting Kombucha at Home: Frequently Asked Questions (2026) · read on October 20, 2026

  21. 21

    BCCDC: ferment long enough for alcohol to drop, without getting too acidic

    “Fermentation must be long enough to lower alcohol, but not too long to avoid extreme low pH and acid build-up.”

    BC Centre for Disease Control, Environmental Health Services · Safety of Fermented Foods, Section 3.11: Kombucha and Jun (September 2023, updated December 2024) · read on October 25, 2026

  22. 22

    Milk kefir fermented past 48 hours can go above 1.1%

    “Fermentation times greater than 48 hrs may lead to alcohol contents of >1.1% ABV.”

    BC Centre for Disease Control, Environmental Health Services · Safety of Fermented Foods, Section 3.12: Kefir, milk and water (December 2024) · read on October 25, 2026

  23. 23

    More water kefir grains, more alcohol

    “Higher volumes of water kefir grains can consume sucrose rapidly in the first 24 hours of fermentation, leading to higher alcohol contents.”

    BC Centre for Disease Control, Environmental Health Services · Safety of Fermented Foods, Section 3.12: Kefir, milk and water (December 2024) · read on October 25, 2026

  24. 24

    Sugar and flavorings added afterward can make excess alcohol

    “Sugars and flavourings with added sugar added after this second step may cause formation of excess alcohol if fermentation persists.”

    BC Centre for Disease Control, Environmental Health Services · Safety of Fermented Foods, Section 3.11: Kombucha and Jun (September 2023, updated December 2024) · read on October 25, 2026

  25. 25

    Bottled under 0.5%, it can keep fermenting

    “the kombucha beverage could have less than 0.5% alcohol by volume when it is bottled, but the fermentation may continue after bottling.”

    Virginia Cooperative Extension (Virginia Tech) · What do I need to know to sell KOMBUCHA at the farmers market? (FST-297, last reviewed November 2025) · read on October 20, 2026

  26. 26

    Some brands reached 3% inside the bottle

    “Some bottled brands continued to ferment, and produced up to 3% alcohol in the package.”

    BC Centre for Disease Control, Environmental Health Services · Food Safety Assessment of Kombucha Tea Recipe and Food Safety Plan (2015, updated 2020) · read on October 20, 2026

  27. 27

    Longer storage and more heat, more alcohol

    “Increased alcohol concentration has been attributed to longer storage time and higher temperatures (15-20oC).”

    BC Centre for Disease Control, Environmental Health Services · Safety of Fermented Foods, Section 3.12: Kefir, milk and water (December 2024) · read on October 25, 2026

  28. 28

    The fridge holds back alcohol

    “Refrigeration limits alcohol and excessive acid production.”

    Virginia Cooperative Extension (Virginia Tech) · What do I need to know to sell KOMBUCHA at the farmers market? (FST-297, last reviewed November 2025) · read on October 20, 2026

  29. 29

    Flavored, it goes in the fridge and is drunk within 2 days

    “Once flavors have been added kombucha should be stored under refrigeration and consumed within 2 days.”

    University of Georgia Cooperative Extension (National Center for Home Food Preservation) · Crafting Kombucha at Home: Frequently Asked Questions (2026) · read on October 20, 2026

  30. 30

    With air, more acetic acid and less alcohol

    “In the presence of oxygen, AAB proliferate resulting in the production of high acetic acid that may not be aesthetically desirable, although alcohol content will be lower.”

    BC Centre for Disease Control, Environmental Health Services · Safety of Fermented Foods, Section 3.12: Kefir, milk and water (December 2024) · read on October 25, 2026

  31. 31

    The only reliable way to know is to test it

    “The only reliable way to confirm that your product has less than 0.5% alcohol, is to test it.”

    Virginia Cooperative Extension (Virginia Tech) · What do I need to know to sell KOMBUCHA at the farmers market? (FST-297, last reviewed November 2025) · read on October 20, 2026

  32. 32

    Beer and wine methods don't work for kombucha

    “Methods traditionally employed for the quantification of ethanol in beers and wines are not suited and/or do not possess the required accuracy for analysis of kombucha.”

    BC Centre for Disease Control, Environmental Health Services · Food Safety Assessment of Kombucha Tea Recipe and Food Safety Plan (2015, updated 2020) · read on October 20, 2026

  33. 33

    Over 30% of kombuchas tested in British Columbia didn't control their alcohol

    “A survey of kombucha teas in BC found over 30% of samples collected were not compliant in managing alcohol content.”

    BC Centre for Disease Control, Environmental Health Services · Safety of Fermented Foods, Section 3.11: Kombucha and Jun (September 2023, updated December 2024) · read on October 25, 2026

  34. 34

    May contain alcohol: not for young children or during pregnancy

    “May contain alcohol. Not a suitable beverage for young children or during pregnancy.”

    BC Centre for Disease Control, Environmental Health Services · Safety of Fermented Foods, Section 3.11: Kombucha and Jun (September 2023, updated December 2024) · read on October 25, 2026

  35. 35

    At 2% alcohol, 200 ml is already too much for a 10 kg child

    “If a kefir beverage contained only 2% ABV, 200 mL or 2 dL (an amount that is less than one cup, 250 mL) would exceed the 50 mg/dL amount in a 10kg or lighter weight child.”

    BC Centre for Disease Control, Environmental Health Services · Safety of Fermented Foods, Section 3.12: Kefir, milk and water (December 2024) · read on October 25, 2026

  36. 36

    Young children lack the enzyme that breaks down alcohol

    “Young children lack the enzyme alcohol dehydrogenase and have difficulties in metabolizing ethanol.”

    BC Centre for Disease Control, Environmental Health Services · Safety of Fermented Foods, Section 3.11: Kombucha and Jun (September 2023, updated December 2024) · read on October 25, 2026

  37. 37

    Confusion, overheating and fatigue can be poisoning and go unnoticed

    “Acting confused, overheating and fatigue may be symptoms of alcohol poisoning that go unrecognized by care givers”

    BC Centre for Disease Control, Environmental Health Services · Safety of Fermented Foods, Section 3.11: Kombucha and Jun (September 2023, updated December 2024) · read on October 25, 2026

  38. 38

    No alcohol during pregnancy

    “The Public Health Agency of Canada recommends that alcohol is not consumed during pregnancy, and that youth should delay drinking alcohol.”

    BC Centre for Disease Control, Environmental Health Services · Safety of Fermented Foods, Section 3.11: Kombucha and Jun (September 2023, updated December 2024) · read on October 25, 2026

  39. 39

    The risk is higher for young children, the fetus and breastfed babies

    “Alcohol toxicity is weight and dose dependant, therefore risk is higher in lower weight children, to the fetus during pregnancy, and to the infant during breastfeeding.”

    BC Centre for Disease Control, Environmental Health Services · Safety of Fermented Foods, Section 3.11: Kombucha and Jun (September 2023, updated December 2024) · read on October 25, 2026

  40. 40

    Nor for people on certain medications or in recovery from addiction

    “There are those who cannot ingest alcohol as it may interfere with prescription medications, have underlying health conditions, or are recovering from alcohol addiction issues.”

    BC Centre for Disease Control, Environmental Health Services · Safety of Fermented Foods, Section 3.11: Kombucha and Jun (September 2023, updated December 2024) · read on October 25, 2026

  41. 41

    Nor for drivers who don't know they may contain alcohol

    “Others may be driving professionally and are unaware that these beverages may contain alcohol.”

    BC Centre for Disease Control, Environmental Health Services · Safety of Fermented Foods, Section 3.11: Kombucha and Jun (September 2023, updated December 2024) · read on October 25, 2026

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