Kombucha sugar, caffeine and calories explained
Is kombucha caffeinated, and how much sugar and how many calories does it have? Per-serving ranges, label tips, sugar-free claims and weight-loss evidence.
Kombucha does contain some sugar and a little caffeine, but usually much less than people expect. Sugar is added to the tea to feed the fermentation, and the culture converts a good share of it into acids, carbonation and traces of alcohol. Commercial kombuchas typically contain around 2.5–4 g of carbohydrate and 10–17 kcal per 100 mL, and only a fraction of the caffeine in a cup of tea.
Below are verified per-serving numbers for sugar, caffeine and calories, plus how to read the label and what the evidence says about weight loss.
Why does kombucha need sugar?
Sugar is the fuel. Yeasts in the SCOBY split sucrose into glucose and fructose, then ferment them into alcohol and CO₂. Acetic acid bacteria convert much of that alcohol into acetic and other organic acids. No sugar, no fermentation — and no tangy, fizzy drink.
Published recipes and studies typically start with roughly 50–100 g of sugar per litre. As fermentation goes on, sugar drops and acidity rises:
- Short ferment → sweeter, more residual sugar
- Long ferment → more sour, less sugar (eventually heading towards vinegar)
- Fruit or juice in the second ferment → adds sugar and calories back
How much sugar is in kombucha?
In Yang et al. (2022, Nutrients), which analysed nine commercial kombuchas sold in the US, label values ranged from about 2.4 to 4.1 g of carbohydrate and 10 to 17 kcal per 100 mL. One “zero” product listed only about 3 kcal per 100 mL.
For context, regular cola contains about 10–11 g of sugar per 100 mL — so a typical commercial kombucha has roughly a third of the sugar of a standard soft drink.
Homemade kombucha is much less predictable. Starting sugar, time and temperature all change how much is left, and you cannot know without measuring. Our guide on how to make kombucha at home covers tasting and pH checks along the way.
Is kombucha caffeinated?
Yes, lightly. Because it is brewed from black, green or white tea, kombucha contains caffeine. How much depends on:
- Tea type and amount — more tea per litre means more caffeine.
- Steeping time — longer steeping extracts more.
- Dilution — many brewers steep a strong concentrate and top up with cold water, which also dilutes the caffeine.
- Added caffeine — some brands add green coffee extract or similar.
Yang et al. measured roughly 15–43 µg of caffeine per mL in products without added caffeine — about 5–14 mg per 330 mL bottle. The one product with green coffee extract measured about 113 µg/mL, or around 37 mg per 330 mL.
Kombucha sugar, caffeine and calories per serving
| Drink | Serving | Carbs / sugar | Calories | Caffeine |
|---|---|---|---|---|
| Commercial kombucha | 250 mL | ~6–10 g carbohydrate | ~25–42 kcal | ~4–11 mg |
| Commercial kombucha | 330 mL | ~8–14 g carbohydrate | ~33–56 kcal | ~5–14 mg |
| Sweetener-based “zero” kombucha | 330 mL | Low sugar (check label) | ~10 kcal | Check label |
| Kombucha with added caffeine | 330 mL | Check label | Check label | Higher (~37 mg in one study) |
| Brewed black tea, unsweetened | 250 mL | 0 g | ~2 kcal | ~50 mg |
| Brewed green tea, unsweetened | 250 mL | 0 g | ~2 kcal | ~26 mg |
| Brewed coffee | 250 mL | 0 g | ~2 kcal | ~80–175 mg |
| Regular cola | 330 mL | ~35 g sugar | ~140 kcal | Check label |
Kombucha values are from label and lab data in Yang et al. (2022). Tea and coffee caffeine are scaled to 250 mL from the FDA’s figures for a 12 fl oz (355 mL) serving: black tea 71 mg, green tea 37 mg, coffee 113–247 mg.
In other words, a bottle of kombucha without added caffeine typically has less caffeine than a small, weak cup of tea. The FDA notes that 400 mg a day is an amount not generally associated with negative effects for most healthy adults. If you are pregnant, see our article on kombucha during pregnancy — many guidelines advise keeping caffeine under 200 mg a day in pregnancy.
How many calories are in kombucha?
Most of kombucha’s calories come from residual sugar, with a small contribution from organic acids and trace alcohol. With typical label values of 10–17 kcal per 100 mL:
- 250 mL glass: about 25–42 kcal
- 330 mL bottle: about 33–56 kcal
- Sweetener-based versions: can be around 10 kcal per 330 mL
Flavoured kombuchas with added juice can be higher — always check the nutrition panel.
How to read a kombucha label
Ignore the front-of-pack slogans and go to the nutrition table. The “of which sugars” (EU/Türkiye) or “Total Sugars” (US) line tells you what is actually left.
What the common claims mean:
- EU and Türkiye: under the EU nutrition claims rules, which Türkiye’s Food Codex mirrors, “sugar-free” means no more than 0.5 g of sugar per 100 mL and “low sugar” means no more than 2.5 g per 100 mL for drinks. “No added sugars” means none was added — it does not mean the drink contains no sugar.
- US: labels show both Total Sugars and Added Sugars, and “sugar free” claims are limited to products with less than 0.5 g of sugar per serving.
Rules are updated from time to time, so producers labelling a product should confirm the current text with the relevant authority or a food technologist.
Sugar-free kombucha and sweeteners
Most “zero” kombuchas are still fermented with sugar; sweeteners such as erythritol or stevia are added afterwards for taste. That cuts calories but changes the flavour, and sugar alcohols like erythritol can cause bloating or gas in some people at higher doses.
Is kombucha good for weight loss?
Short answer: kombucha is a low-calorie drink, but there is no evidence that it causes weight loss.
- A 2019 systematic review found only one study that measured kombucha’s effects in humans.
- A small 2023 pilot trial in 12 adults with type 2 diabetes reported lower fasting blood glucose after four weeks of kombucha. The sample was tiny, drop-out was high, the drinks were donated by a producer, and body weight was not an outcome.
The practical effect is simpler: swapping a 330 mL regular cola for the same amount of kombucha saves more than 20 g of sugar and 80+ kcal. The WHO recommends keeping free sugars below 10% of daily energy, ideally below 5% (about 25 g) — and the sugar in kombucha counts towards that.
If you have diabetes or are tracking blood sugar, count kombucha like any other sweetened drink and talk to your doctor or dietitian. For a broader view, see kombucha benefits and side effects.
Does the alcohol add calories?
Fermentation produces a little alcohol, which technically adds calories, but in well-managed kombucha the amount is very small. Yang et al. measured 0% to 1.29% ethanol across the products tested. For thresholds and the halal question, read is kombucha alcoholic? At our Fethiye brewery we keep finished kombucha at 2–4 °C, because cold storage slows the fermentation that would otherwise keep turning sugar into alcohol in the bottle.
The bottom line
Kombucha is not sugar-free, but it is a low-sugar, low-calorie, lightly caffeinated drink. A typical commercial 330 mL bottle has around 33–56 kcal and 5–14 mg of caffeine. Read the sugars line, watch out for juice-heavy flavours, and treat kombucha as a lighter alternative to soft drinks rather than a diet tool.
Want to try live, cold-chain kombucha brewed in Fethiye? See our kombucha.
This article is general information, not medical advice.
Frequently asked questions
Is kombucha caffeinated?
Yes, lightly. Kombucha is brewed from tea, so it contains some caffeine, but measured levels in products without added caffeine were around 5–14 mg per 330 mL — far less than a cup of tea or coffee.
How much sugar is in kombucha?
Commercial kombucha labels typically list about 2.4–4 g of carbohydrate per 100 mL, so a 330 mL bottle has roughly 8–14 g. That is about a third of the sugar in the same amount of regular cola.
How many calories are in kombucha?
Most commercial kombuchas list around 10–17 kcal per 100 mL, so about 25–42 kcal per 250 mL glass and 33–56 kcal per 330 mL bottle. Sweetener-based “zero” versions can be closer to 10 kcal per bottle.
Is kombucha good for weight loss?
There is no good evidence that kombucha itself causes weight loss. It can help indirectly if it replaces higher-sugar drinks such as regular soda or juice.
Can kombucha be sugar-free?
Kombucha cannot be brewed without sugar, because sugar feeds the fermentation. Low- or zero-sugar versions either ferment longer or replace residual sweetness with sweeteners like stevia or erythritol — check the sugars line on the label.
Will kombucha keep me awake?
For most people, unlikely: a bottle without added caffeine has less caffeine than a weak cup of tea. If you are very caffeine-sensitive, avoid it late in the day and check labels for added caffeine such as green coffee extract.