Kombucha Tea Nutrition Facts

Kombucha Tea provides about 13 calories, 15.8 g of carbohydrates, and 2 g of sugar per 100 g (3.5 oz), with virtually no protein, fat, or fiber. It is fermented sweet tea — tea leaves, sugar, water, and a live culture — so its numbers depend on fermentation time and on whatever juice or sweetener is added before bottling. That is why two bottles of the same size can differ by 10 g of sugar or more.

🍵 What Kombucha Tea Is

• Base: brewed black or green tea sweetened with sugar, which feeds the culture.
• Culture: a SCOBY — a symbiotic culture of bacteria and yeast — ferments the tea for roughly 7–14 days.
• Output: acetic, gluconic, and lactic acids, carbon dioxide, trace ethanol, and live microorganisms.
• Finishing: most commercial bottles get fruit juice, puree, or extra sugar for flavor after primary fermentation.
• Standard pours in the US and Canada: 8 fl oz (240 mL, 1 cup), 12 fl oz (355 mL), and 16 fl oz (473 mL).

The table below is the reference panel for this entry, sourced from USDA FoodData Central (FDC 2003593). Because kombucha is a live product, treat any single table as a baseline and read your bottle's label.

🔥 Calories and Carbs per Serving

One cup of kombucha lands near 31 calories, which makes it one of the lighter drinks in the fridge — well below soda, sweetened iced tea, or juice. Double the cup column for a 16 fl oz (473 mL) bottle and you are still around 62 calories with roughly 9.6 g of sugar. The catch is carbohydrate volume: 38 g per cup is substantial for anyone counting carbs, so check whether your brand ferments longer or dilutes with water before drinking.

🍞 Sugar, Fiber, and the Fermentation Question

Fermentation consumes sugar, which is why good kombucha tastes tart rather than syrupy. In practice, bottled brands range from about 2 g to 20 g of sugar per serving, depending on how dry the brew is and how much juice is added back.

• Dry or original brews usually sit at the low end — often 2–6 g of sugar per 8 fl oz cup.
• Flavored bottles can approach soda levels, especially 16 fl oz sizes drunk as a single portion.
• Fiber is 0.0 g, so kombucha contributes nothing toward the 25–30 g of daily fiber most adults aim for.

Watch out: A 16 fl oz flavored bottle can carry as much sugar as a can of soda. If sugar is your reason for switching, buy unflavored or low-sugar labels and check grams per bottle, not grams per 100 mL.

💪 Protein, Fat, and Micronutrients

Protein at 0.09 g and fat at 0.27 g per 100 g are rounding-error amounts — kombucha is not a protein or fat source and should never be counted as one. The panel lists no vitamins above trace levels and only 5 mg of sodium per 100 g (about 12 mg per cup), so it is not a meaningful source of electrolytes either.

Some lab analyses of fermented tea report small amounts of B vitamins and tea polyphenols carried over from the green or black tea base. Those amounts are not standardized across brews and are not captured as meaningful values here, so treat them as a bonus rather than a reason to drink it.

🍵 Probiotics, Polyphenols, and the Evidence Base

Kombucha carries live yeast and bacteria, which is the main reason people drink it. Human evidence is still thin: most studies are small, short, or in animals, and reviews consistently call for larger controlled trials before any disease claims are made.

• Gut health: the culture may support a more diverse microbiome, but strain counts and CFU levels vary enormously between products — and many bottled brands are pasteurized, which removes live cultures.
• Blood sugar: a few small trials in adults with type 2 diabetes reported modest fasting glucose improvements; these are preliminary, not prescriptive.
• Antioxidants: tea polyphenols survive fermentation in reduced amounts, so the effect is smaller than drinking the brewed tea itself.

Anyone who is pregnant, immunocompromised, or managing a chronic condition should talk with a clinician before drinking unpasteurized kombucha.

⚖️ Where It Fits: Weight Loss, Keto, and Diabetes

At roughly 13 kcal per 100 g, kombucha is not calorie-dense — a cup is about 31 calories. It supports weight loss only as a replacement for sugary drinks, not as an addition, and the 38 g of carbohydrate per cup still counts against a daily budget. For keto, 15.8 g of net carbs per 100 g is too high for most people's macros, and even a small glass can consume a quarter of a 50 g carb allowance.

The panel lists no glycemic index, and published GI values for kombucha are not established. With 2 g of sugar per 100 g, a dry brew is unlikely to spike blood sugar sharply, but sweetened bottles behave differently — test with a meter if you monitor glucose. Compare kombucha with green tea or kefir if you want lower-sugar fermented options, and check the nutrition calculator to see how a bottle shifts your daily totals.