What Pasteurisation Kills (And Why We Don't Do It)

What Pasteurisation Kills (And Why We Don't Do It)
What Pasteurised Actually Means — Canbo
The Product

Most fermented food
isn't fermented.

Canbo How it's made 6 min read

Walk down the fermented foods aisle in most UK supermarkets and you will find products that are, technically, not fermented. They are acidified. The bacteria are dead. The cultures are gone. The label says fermented. The product is not.

Vinegar is added to replicate the sour flavour that fermentation produces naturally. The product is then pasteurised — heated to a temperature that kills all bacterial activity — and sealed for a shelf life of twelve to eighteen months.

This is not a niche problem. It is the dominant production method for the fermented foods category in mass-market retail. It is cheaper, more consistent, easier to distribute, and it satisfies the letter of the labelling requirement without the spirit of it.

Canbo does not do this. Every jar leaves us unpasteurised. This is not a marketing decision. It is a commitment to making something that is actually what it says it is.

What pasteurisation does

Pasteurisation was developed by Louis Pasteur in the 1860s as a method of killing pathogens in wine and beer. The principle is straightforward: heat the product to a sufficient temperature for a sufficient time to eliminate harmful microorganisms.

It works. Pasteurisation has prevented enormous amounts of foodborne illness. For many products, it is the right call. For fermented vegetables, it is the wrong call.

What dies
The lactic acid bacteria that drove the fermentation — primarily Lactobacillus species. They lower the pH, produce the complex flavour, and make the product what it is. Pasteurisation kills them all.
What's left
A product that was fermented — past tense — and is now dead. The flavour profile is there, at least partially. But the living component, the thing that makes fermented food different from pickled food, is gone.
The irony
The bacteria that drive lacto-fermentation produce lactic acid, acetic acid, and a range of other compounds that give fermented food its depth. When you kill them, you lose the very mechanism that made the product worth eating.

What live cultures actually means

The phrase appears on a lot of food packaging. It means different things in different contexts. In properly made fermented vegetables, it refers to the naturally occurring lactic acid bacteria that were present on the raw ingredient and drove the fermentation from start to finish.

Where they come from
Not added. Not manufactured. They come from the vegetable itself, from the air in the fermentation environment, from the water in the brine. The salt concentration and acidic environment select for them — they dominate as the ferment progresses.
In every Canbo jar
When you open a Canbo jar, those bacteria are still there. Still active. The jar is still fermenting, slowly, at whatever temperature your fridge is running at. This is why the product changes over time — getting sharper, more complex, more deeply flavoured as the weeks pass.
The fizz
The bacteria produce carbon dioxide as a byproduct of fermentation. A cold jar builds up a small amount of pressure. When you open it, that pressure releases. It is not a flaw. It is evidence that what's in the jar is alive.
The cost of doing it properly

Unpasteurised means cold chain. All the way.

From the moment a jar leaves our kitchen to the moment it reaches your fridge, it needs to be kept cold. This is more expensive. It is more logistically complex. It limits distribution options. It is one of the reasons that genuinely live fermented products are harder to find than their pasteurised equivalents.

We think it's worth it. The product that requires cold chain is a fundamentally different product from the one that doesn't. One is alive. The other isn't. We are only interested in making the alive version.

A note on shelf life

Unpasteurised fermented vegetables, kept refrigerated, have a shelf life of several months. The acidity of the product is a natural preservative. The salt is a natural preservative. The live cultures actively outcompete spoilage organisms. Properly made fermented vegetables are not fragile.

Week two
Brighter, more lactic, cleaner. The fermentation is still early. The flavour is fresh and sharp without much depth underneath it yet.
Week eight
Deeper, sharper, more complex. The cultures have had time to develop. The flavour has a different quality — layered, more interesting, more itself.
The point
The product has a trajectory. It rewards attention and rewards returning to it. This is not a compromise. It is a feature. Alive things change. That's how you know they're alive.

Most of what's sold as fermented food in the UK is not fermented in any meaningful sense. It is acidified, pasteurised, and shelf-stable. It is a different product wearing the same label.

Every Canbo jar is alive when it reaches you. It was alive when it left us. The difference is not a claim. It is a method. And it is the only way we know how to make something worth eating.

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