Pasteurised, what does it actually mean? (And how does it affect what's in your glass?)

March 5, 2026

It's the kind of word you see on a label and politely ignore. However, in the world of fermented drinks, it tells an important story: a drink that has been heated to make it ‘safe’ and stable.

Pasteurisation: a simple definition

Pasteurisation is a process that involves heating food or drink to a specific temperature for a given period of time in order to destroy microorganisms and inactivate harmful ones (bacteria, mould, etc.). The aim is to make the product more stable and, above all, to make it last longer. ¹²³

There are two main methods:

LTLT pasteurisation (low temperature long time): The product is heated gently (63°C to 69°C) for 30 minutes. This is often used by smaller producers. ²³⁴
Flash pasteurisation: The product is heated to a very high temperature for a very short time (e.g. 72°C for 15 seconds for milk). This standard in industry for juices and mass-produced beer. ²³⁵

Why pasteurise? (Three practical reasons) ¹³

Safety: To drastically reduce pathogens.
Preservation: To prevent the drink from going off over time.
Stability: To facilitate transport and storage (e.g. it can be stored outside the fridge).

A brief history lesson: from Louis Pasteur to our bottles

Back in the 19th century, wine and beer tended to go off without warning. Opening a bottle was a bit like playing the lottery. After investigating, Louis Pasteur realised that it wasn't ‘evil spirits’ in the barrel, but microorganisms that were disrupting fermentation.

In 1865, he filed a patent for this heat-treatment process applied to wine: pasteurisation was born. Since then, the principle has been extended to milk, juices and even some mass-produced kombuchas. Yes, unfortunately... ⁶⁷⁸

Unpasteurised: more alive... but more demanding

At Smile, our kombuchas are unpasteurised. That’s an obvious choice for us, because kombucha is a living drink: it is full of good bacteria for your gut microbiome that support digestion. ⁹¹⁰

The dilemma:

If we pasteurize, we get a product that can sit outside the fridge with a two-year shelf life. We lower our costs and make our lives much easier. But the drink loses its added value. In other words, it no longer delivers on its promises.

If we choose not to pasteurize, we take the harder road: mandatory cold chain, a living beverage that continues to evolve gently over time, smaller and more frequent production batches to ensure the kombucha is always at its freshest.

But we keep a living kombucha, with the full richness of its microorganisms and their benefits. ⁹¹¹(Link to FAQ: Why kombucha is good for you)

We're not going to lie to you: it's not the ‘business-smart’ choice. It requires patience (we let nature do its job, and it takes its time).

It requires a strict cold chain : a huge cold room at the brewery, refrigerated transport, and space in the fridges of shops, restaurants and bars.
And because our drinks are full of life, their taste can vary slightly. That's also the beauty of living things. Long live diversity!

But if it's not pasteurised, isn't it risky?

Kombucha is a drink that naturally becomes more acidic over time. This is one of its historical strengths: this acidity kept the drink healthy and drinkable long before the invention of frigoboxes!

At Smile, our brews reach full maturity when their pH drops to 3.5 or below (and when our brewers approve the taste - always delicious). At this level of acidity, pathogenic bacteria simply cannot survive, let alone grow. The drink is and remains safe, while still being raw.

Unpasteurised is not the easiest route, but it is the one that respects the product and its raison d'être. At Smile, we keep it alive, and we keep it cool.

Fresh with benefits.

‍

Disclaimer:

This article is for informational purposes only and does not constitute medical advice. Pasteurisation is a food science topic, not a lifestyle prescription. If you have specific health concerns about fermented drinks, your doctor remains the right person to consult. We handle the cold chain. They handle the rest.

‍

Sources:

Codex Alimentarius Commission. (1999). Heat treatment definitions (CX/MMP 00/15) (Agenda Item 5). Food and Agriculture Organization of the United Nations/World Health Organization. https://www.fao.org/fao-who-codexalimentarius/sh-proxy/en/?lnk=1&url=https%253A%252F%252Fworkspace.fao.org%252Fsites%252Fcodex%252FShared%2BDocuments%252FArchive%252FMeetings%252FCCMMP%252Fccmmp4%252Fmm00_15e.pdf
Food and Agriculture Organization of the United Nations. (s. d.). [FAO document “j2308e02” – section pasteurization time/temperature] (72 °C/15 s ; 63 °C/30 min). https://www.fao.org/4/j2308e/j2308e02.htm
Canadian Food Inspection Agency. (2023, 26 juin). Dairy processing: Batch pasteurization systems. Gouvernement du Canada. [https://inspection.canada.ca/en/preventive-controls/dairy-products/batch-pasteurization?](https://inspection.canada.ca/en/preventive-controls/dairy-products/batch-pasteurization?utm_source=chatgpt.com)
Canadian Food Inspection Agency. (2024, 17 juin). Dairy processing: High temperature short time (HTST) pasteurization systems. Gouvernement du Canada. [https://inspection.canada.ca/en/preventive-controls/dairy-products/htst?](https://inspection.canada.ca/en/preventive-controls/dairy-products/htst?utm_source=chatgpt.com)
National Academies Press. (2003). Scientific criteria and performance standards to control hazards in dairy products. In Scientific criteria to ensure safe food. NCBI Bookshelf. https://www.nationalacademies.org/read/10690/chapter/9#233
Institut Pasteur. (2024, 19 juin). La vie et l’œuvre de Louis Pasteur. https://www.pasteur.fr/fr/institut-pasteur/notre-histoire/vie-oeuvre-louis-pasteur
Encyclopaedia Britannica. (2026, 14 février). Louis Pasteur: Research career.
Wikipedia contributors. (s. d.). Louis Pasteur. Wikipédia. Consulté le 23 février 2026. [https://en.wikipedia.org/wiki/Louis_Pasteur?](https://en.wikipedia.org/wiki/Louis_Pasteur?utm_source=chatgpt.com)
O’Sullivan, E. N., & O’Sullivan, D. J. (2024). Viability and diversity of the microbial cultures available in retail kombucha beverages in the USA. Foods, 13(11), 1707. [https://www.mdpi.com/2304-8158/13/11/1707?](https://www.mdpi.com/2304-8158/13/11/1707?utm_source=chatgpt.com)
Dimidi, E., Cox, S. R., Rossi, M., & Whelan, K. (2019). Fermented foods: Definitions and characteristics, impact on the gut microbiota and effects on gastrointestinal health and disease. Nutrients, 11(8), 1806. https://www.mdpi.com/2072-6643/11/8/1806
Onsun, B., Toprak, K., & Sanlier, N. (2025). Kombucha tea: A functional beverage and all its aspects. Current Nutrition Reports, 14, 69. [https://link.springer.com/article/10.1007/s13668-025-00658-9?](https://link.springer.com/article/10.1007/s13668-025-00658-9?utm_source=chatgpt.com)
Sreeramulu, G., Zhu, Y., & Knol, W. (2000). Kombucha fermentation and its antimicrobial activity. Journal of Agricultural and Food Chemistry, 48(6), 2589–2594. https://pubs.acs.org/doi/10.1021/jf991333m
European Commission. (s. d.). Biological safety (Food Safety).https://food.ec.europa.eu/food-safety/biological-safety_en

‍