Lactose Intolerance and Lacto fermentation

Can you eat fermented foods if you’re lactose intolerant? Because fermented vegetables often are called “lacto fermented,” some think that people who are lactose intolerant cannot eat fermented vegetables. However, that is usually not the case. Read on for more information on this oft-confused topic.

Can you eat fermented foods if you’re lactose intolerant?

What is lacto fermentation?

Lacto-fermentation is a way of preserving food.  Plants, especially organically grown plants, are full of microbes, both good and bad. When vegetables are fermented they either will be salted or submerged in brine. The salt in the fermentation pulls water out of the produce and when all of the produce is submerged under the juice, it creates an anaerobic situation.

Most microbes need oxygen to survive but not the  lactobacillus bacteria family– which are the good guys. As the produce sits in the liquid without oxygen the good guys overtake the bad guys and in a few days you have food that is not only preserved but actually has more nutritional value and is easier to digest than the original produce.

The “lacto” in lacto-fermentation refers to the lactobacillus bacteria converting sugars into lactic acid.  The lactobacillus bacteria was first discovered in milk ferments. However, not all strains convert lactose, some convert other sugars, like the ones found in vegetables.

Fermented vegetables (usually) do not have lactose or casein them.  Sometimes there is confusion because it’s the lactobacillus family of bacteria that makes milk acid form dairy ferments such as yogurt and cheese. Yogurt and cheese do have lactose and casein in them but it’s because these are in the milk, not because they are lacto-fermented.

But what about the whey?

To complicate this discussion just a bit, some recipes call for a whey starter. While this might speed up the the beginning process, it is an unnecessary step. The vegetables already have the on them all that they need to be able to ferment. The process of these bacteria converting sugars to lactic acid will happen without adding whey.

Also, sometimes whey can leave a sour milk or cheesy flavor in the ferment. And while you might like cheese, you probably don’t want your sauerkraut or peppers tasting like cheese.

If you’re lactose intolerant you do need to be aware that some people use whey in their ferments. This is why I stated that there is “usually” no lactose or casein in ferments. If whey is used as a starter then there could be lactose or casein in the vegetable ferment. If you are sensitive to lactose or casein, you’ll want to ask if you didn’t make the ferment.

Eating lacto-fermented foods is a wonderful part of a healthy diet. The same lactobacillus bacteria that is found on all plants is also present in our guts and mouths (among other places). This bacteria plays a key role in keeping our gastrointestinal tracts healthy, and the best way to replenish this bacteria is to eat fermented foods.


If you want to embark on a fermentation journey, start at the Fermentools store. There you will find kits put together just for the beginner in mind. They include fermentation lids for Mason jars, glass fermentation weights, airlocks, salt, and more.


Angi Schneider is a minister’s wife and homeschooling mom. She is passionate about growing food for her family and living a simple life. She blogs their homesteading and homeschooling adventures at and is the author of The Gardening Notebook which she wrote to help other gardeners remember all the great information they are learning.

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