Pickling vs Fermenting: What's the Difference?

Pickling vs fermenting: when you walk through the supermarket, you'll see all kinds of preserved vegetables, from gherkins and onions to sauerkraut and kimchi. But are those crunchy dill pickles made by pickling or by fermenting? And what about that jar of sauerkraut: does it contain live cultures? Don't worry, we're here to clear up the confusion and help you tell the difference next time you shop for your favourite preserved foods.

Pickling vs fermenting: a brief overview

Pickling is a preservation method that uses an acidic solution, usually vinegar, to protect vegetables and other foods from spoilage. The acidity of the vinegar creates an environment where harmful bacteria can't survive, so the food stays safe to eat.

Fermentation, on the other hand, is a natural process driven by beneficial microorganisms such as lactic acid bacteria. Vegetables are usually submerged in a salt brine, and these friendly bacteria turn sugars into lactic acid, which preserves the food and gives it unique flavours.

	Pickling	Fermentation
Key ingredient	Vinegar	Saltwater brine
Method	Vegetables are submerged in a vinegar-based solution. Quicker process: ready to eat in hours or days.	Beneficial bacteria convert sugars into lactic acid, preserving the food. Slower process that can take days, weeks or even months.
Result	Sharp, tangy flavour from the vinegar.	Unique, tangy and more complex flavour.
Living bacteria	No live bacteria	Can contain live cultures (if unpasteurised).
Examples	Pickled cucumbers, gherkins and onions.	Kimchi, sauerkraut and traditional lacto-fermented pickles.

Watch out: not all that glitters is gold

Not every kimchi, sauerkraut or pickle you find in shops has actually been fermented. And even when they have, not all of them still contain live bacteria.

On the one hand, fermentation is a longer and more complex process, which is usually less attractive financially for food companies. That's why many brands make their kimchi, sauerkraut or pickles with vinegar instead of letting them ferment.

On the other hand, fermented products are less stable than pickled ones because they contain living microorganisms. These little guys keep fermenting the product, even in a sealed jar, especially at higher temperatures. The only way to slow them down is to keep the jar cold. That's why many companies pasteurise their products after fermentation, so they can sit at room temperature for years.

Choosing between pickled and fermented products ultimately comes down to taste. Pickles are crisp, tangy and have a distinct vinegar kick, while fermented foods offer a broader range of flavours and can contain live cultures when they are not pasteurised, like our raw kimchi.

Here are some tips to help you make an informed choice next time you buy preserved foods:

Cracking the code: how to tell them apart

1. Read the label: pickled products will usually list vinegar as an ingredient. Keep in mind that some fermented foods also contain a little vinegar for flavour or preservation, so this isn't foolproof.

2. Check the ingredient list: for pickled foods, vinegar should be one of the main ingredients. For fermented foods, you may see "fermented" or "cultured" next to the vegetable ingredients.

3. Look for living microorganisms: fermented foods such as kimchi or sauerkraut may mention "live cultures", "lactic acid bacteria" or "it's alive" on the label. Note that the word "probiotics" is strictly regulated and not allowed on most food labels in Switzerland and the EU.

4. Storage: fermented products usually need to be refrigerated to keep the cultures alive and slow down fermentation, while vinegar pickles can sit on the shelf. That said, some shops refrigerate both for freshness, and some keep fermented products at room temperature for lack of space.

5. Shelf life: check the best before date. Raw fermented vegetables like kimchi or sauerkraut usually keep for up to 1 to 2 years in the fridge and no more than 6 to 12 months at room temperature.

Keep these tips in mind on your next supermarket adventure, and you'll be able to pick the perfect jar of pickles or fermented vegetables for your taste buds. And remember, there's no wrong choice: pickling and fermenting both offer unique and delicious ways to enjoy preserved vegetables. Happy shopping!