Industrial kombucha is consistent, needs no work, and is often pasteurised, which removes the live cultures. Homemade kombucha lets you set the fermentation time, and therefore the sugar between 1 and 5 g per 100 ml and the acidity, and it always contains live cultures. A flavoured shelf bottle can carry 6 to 9 g of sugar per 100 ml, close to a soft drink. Neither is better: they answer two different questions.
The comparison is usually made badly, with homemade presented as pure and industrial kombucha as a fraud. That is not accurate. What actually differs is control, consistency and what the label does or does not say. This page sets out the nine points that change a decision, and what to read on a bottle.
Two rows carry most of the weight. Pasteurisation decides whether there are live cultures in the bottle, and fermentation time decides the sugar and the acidity. Everything else follows from those two. An unpasteurised industrial kombucha is much closer to a home batch than to a pasteurised one from the same shelf.
Pasteurisation is not a fault. It is what makes a stable product possible in a warm warehouse. It simply means the main argument used to sell kombucha, live cultures, no longer applies to that bottle.
| Per 100 ml | Homemade | Plain industrial | Flavoured industrial |
|---|---|---|---|
| Sugar | 1 to 5 g, by time | 2 to 5 g | 6 to 9 g |
| Energy | 15 to 30 kcal | 15 to 30 kcal | 30 to 45 kcal |
| Caffeine | from the tea | from the tea | from the tea |
| Alcohol traces | up to about 1 per cent | under 0.5 per cent | under 0.5 per cent |
| Live cultures | always | only if unpasteurised | only if unpasteurised |
| Added juice or sugar | only if you add it | rare | common |
This is where the useful comparison lies. A plain industrial kombucha and a home batch are close on sugar. A flavoured one is a different product: the juice added after fermentation brings the figure up, and at 8 or 9 g per 100 ml the distance from a soft drink is mostly the label.
Four words decide almost everything: unpasteurised, live, sugar and the position of added sugar in the ingredient list. If a bottle of industrial kombucha does not state a sugar figure per 100 ml, that is itself the answer.
| Variable | At home | In a bottle |
|---|---|---|
| Fermentation time | 7 to 12 days, your call | fixed by the producer |
| Residual sugar | follows from the time | printed, not adjustable |
| Acidity | taste and stop | fixed |
| Tea used | your choice | stated, sometimes vaguely |
| Flavouring | fruit in the second fermentation | often juice added after |
| Fizz | second fermentation length | often force carbonated |
Read that list and the trade becomes clear. Industrial kombucha buys you consistency and zero effort, and costs you every one of those six settings. Fifteen minutes every ten days buys them all back.
| After 12 months | Homemade | Industrial |
|---|---|---|
| Purchases of culture | 1 | not applicable |
| Consumables per litre | 6 to 8 g tea, 70 to 90 g sugar | full price per bottle |
| Bottles | the same ones, reused | one per serving |
| Total effort | about 9 hours | shopping and carrying |
| What is left at the end | several spare SCOBY layers | nothing |
The last row is the structural difference. A live culture is larger at the end of the year than at the start, which no purchased product can be.
Knowing the process explains most of the differences on the label. Large scale production is not a corrupted version of the home method, it is a different method built around predictability.
| Stage | At home | At scale |
|---|---|---|
| Culture | a solid SCOBY passed from batch to batch | selected strains dosed into each tank |
| Temperature | whatever the room is | held to within a degree |
| Duration | tasted and stopped when right | fixed, measured by pH |
| Filtration | a sieve | fine filtration, removes yeast strands |
| Carbonation | a second fermentation in the bottle | usually injected gas |
| Stabilisation | none, it keeps fermenting in the fridge | pasteurisation or cold chain |
| Flavour | fruit in the second fermentation | juice or flavouring after fermentation |
Two of these stages are the ones people object to, and both are understandable. Filtration removes the strands that make a home batch look alive, and injected carbonation replaces a second fermentation that would keep working on a shelf. Neither is dishonest. But together they explain why industrial kombucha looks and behaves like a soft drink even when it is not one.
These three patterns cover most of what is on a shelf. None of them is a trick, but they are not equivalent.
The word to look for is unpasteurised. If it is absent, assume the bottle has been heat treated. Producers who do not pasteurise say so, because it is their main selling point.
This is the most useful thing to do with a shop bottle: use it as a target. If you know the sugar figure you liked, you can reproduce roughly the same profile at home.
| If the bottle had | Ferment for | Second fermentation |
|---|---|---|
| 2 to 3 g sugar, quite sour | 11 to 12 days at 22 C | 2 days |
| 4 to 5 g sugar, balanced | 8 to 10 days at 22 C | 3 days |
| 6 to 7 g sugar, mild | 7 days at 22 C | 3 days plus 50 ml juice |
| Strongly fizzy | any of the above | 3 to 4 days sealed, then cold |
| Very smooth, no strands | any of the above | strain twice through a fine sieve |
The last row is worth noting. Most of what makes a home batch look different from an industrial kombucha is removed by straining it properly. It is a cosmetic difference, not a quality one.
These apply to us as much as to anyone. A company selling fermented drinks or cultures should be able to answer all five.
We sell live cultures for home fermentation, and our answer to the first question is that nothing we ship is pasteurised, because it would not work. Our answer to the second is that it depends on how long you ferment, which is precisely the point of this page.
We sell cultures, and we still think those four cases are real. Starting a jar you will abandon in three weeks is worse than buying a bottle.
Authorised health claims in the European Union are listed by the European Food Safety Authority. The sugar figures above, on the other hand, are printed on every bottle you can compare.
Live kombucha SCOBY
Shipped with its own starter liquid, ready for a first batch the day it arrives.
See the SCOBYThe step by step method: how to make kombucha. Troubleshooting a batch: sick kombucha.
Not better, different. Homemade lets you set the fermentation time and therefore the sugar and acidity, and it contains live cultures. Industrial kombucha is consistent and requires no work, but is often pasteurised, which removes the live cultures.
Only if the label says unpasteurised. Heat treatment gives a longer shelf life and a stable product, and it ends the life in the bottle. Many shelf products are pasteurised and do not state it prominently.
Typically 2 to 5 g per 100 ml for a plain version, and 6 to 9 g for one flavoured with juice. The figure is on the label. Homemade sits at 1 to 5 g depending on how long you ferment.
Because the variables are removed. Selected strains, a controlled temperature and a fixed fermentation time produce an identical result. A home batch shifts with the season, which some people like and others do not.
Not entirely. Fermentation produces traces in any kombucha, usually under 0.5 per cent in commercial products because they are controlled to stay below the legal threshold. Home batches can go slightly higher.
Homemade, by a wide margin, once the culture is bought. After that a litre costs only tea and sugar, and the SCOBY multiplies rather than being consumed.
Only an unpasteurised, unflavoured one, and it takes two to four weeks with a high failure rate. A live SCOBY with starter liquid is the reliable route.
Some flavoured versions come close on sugar. Read the figure per 100 ml: at 8 or 9 g the difference from a soft drink is mostly the name on the bottle.
