Lacto-Fermentation for Beginners

lacto-fermentation for beginners

What is lacto-fermentation?

Lacto-fermentation is a way of preserving food that has been part of traditional diets all over the world for thousands of years.  Food is fermented at room temperature using lactic acid as a preserving agent.

Does lacto-fermentation involve milk products?

No, the “lacto” part of the name comes from the bacteria, Lactobacillus, which get their name from the way they turn lactose and other sugars into lactic acid. Some recipes call for whey (strained from yogurt) as a starter, but I don’t use this in my fermenting and it’s worked out fine.

Won’t leaving food at room temperature poison me?

When I made my first batch of sauerkraut back in 2012, I was convinced I was going to poison myself. How could food stay at room temperature for a week and still be okay to eat, especially in a warm climate like Brisbane?

The secret to successful fermenting is to create an environment where the Lactobacillus bacteria can grow and proliferate, while inhibiting the growth of bacteria that can cause food to spoil. Lactobacillus bacteria are fairly salt-tolerant, so by adding salt to the vegetables initially, the growth of undesirable bacteria can be slowed, while the Lactobacillus bacteria are unaffected.

The Lactobaccillus bacteria then begin to metabolise the sugars and carbohydrates, producing lactic acid and carbon dioxide. The carbon dioxide ensures that the environment stays anoxic (oxygen-free), further inhibiting the growth of undesirable organisms. The lactic acid lowers the pH of the ferment, again making it unsuitable to growth of undesirable organisms.

So if you have fermented correctly, there are three evironmental factors working against the growth of moulds, yeasts and undesirable microorganisms: high salt content, low oxygen content and low pH.

Lacto-fermented carrot sticks

Do I need to use a starter?

Some recipes call for whey or a commercial starter to innoculate the ferment with some Lactobacillus bacteria. This is not necessary, as the vegetables themselves will generally have enough bacteria on them to begin to ferment. However, I do sometimes use a bit of brine from a previous batch as a starter, so if it makes you feel better to use a starter, go ahead!

How do I know if the lacto-fermentation has been successful?

A successful ferment will start bubbling within a day, it will smell sour, and the vegetables will be crunchy and taste pleasantly sour. There may be a small amount of white scum present on the surface – this is safe and you can just skim it off. There will also be a small amount of sediment in the bottom of the jar, this is just a byproduct of the fermentation (similar to the sediment produced in homebrew beer).

An unsuccessful ferment may be slimy, smell bad or turn a different colour. In two years, I have only had two batches go wrong, and it was immediately obvious. One batch of salsa went bad in very hot weather and I could tell because of the smell, and a batch of daikon radishes went mouldy because they were not completely submerged in the brine.

Here are a few handy guides written by people with a lot more experience with lacto-fermentation, that can help you troubleshoot your ferment:

A great troubleshooting guide to fermentation from the National Center for Home Food Preservation. They refer specifically to fermented cucumbers (pickles), but the guide would apply to all types of fermentation.

Another great troubleshooting guide put out by North Carolina State University.

And a very detailed guide from the Food and Agriculture Organisation of the United Nations.

Lacto fermented salsa homemade

Want to give it a go? Here are some easy recipes for beginners:

Sauerkraut (Economies of Kale)
Lacto-fermented salsa (Economies of Kale)
Lacto-fermented carrot sticks (Economies of Kale)
Lacto-fermented garlic (Learning and Yearning)
Lacto-fermented veggies (Simply Smiles)
Lacto-fermented spicy carrots (Happy Mothering)
Cortido (Just Making Noise)
Lacto-fermented radishes (GNOWFGLINS)

Next week I will talk about the benefits of lacto-fermentation, both in terms of health and food preservation.

Do you have any more questions about lacto-fermentation? Do you have any recipes to share?

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  1. Opps I almost missed the comments bit!

    Finally the clues on your lactofermenting hobby! Thanks for sharing – not sure I’ll be doing it, but happy to learn more.

  2. When I was growing up, we called this process pickling. Sauerkraut and pickled green beans were the favorites to make. We didn’t have any starters. We just used natural bacteria and a big crock where things were weighted down with a big river rock. We didn’t have the success rate that you do and when things got slimy instead of pickled, my grandmother always blamed it on the rock being not right.

    • I’ve seen it called pickling as well, but that can be confusing because vinegar pickles are also called pickles. I would really like to get a crock one day, but for the moment I mostly use jars and then either smaller jars or ziploc bags filled with water to weigh down the veggies. I like the idea of using a rock though – no nasty plastic chemicals.

      Do you do any pickling now?

  3. Thanks. Great article. I really want to try more fermenting :).

  4. Thanks for this guide – I do feel a bit nervous about poisoning myself, ha! Though I have actually done fermentation before, but totally different kind, which involved fruit and honey.

    • Did you end up with alcohol when you fermented fruit and honey? I’ve tried making mead that way, but still need to perfect it 🙂

      • Depends how much water you use to cut the honey and how alcohol tolerant the yeast is. But you can get from 9 to 15% abv. Making mead is easy. Easier than wine and beer. Hard cider is by far the easiest.

  5. EcoCatLady says:

    Hmmmm… it looks very interesting. Part of me is tempted to try it, but the other part is remembering how I was in bed for a week with a migraine last time I ate sauerkraut. I wonder if this is the same way sauerkraut is produced commercially, or if there’s something different about the process. Anyhow, I think I’m gonna err on the safe rather than sorry end, but I’m fascinated by the information nevertheless.

    • I have heard of people who are sensitive to yeasts having reactions to lacto-fermented foods, so with your allergies it probably is better for you to be safe than sorry. I think commercially-produced sauerkraut is either made with vinegar, or is pasteurised after it has finished fermenting, which means you don’t get the benefits of lacto-fermentation.

  6. This is fantastic information to have out there. It wasn’t so long ago that the world survived without refrigeration…I look back at all these ‘lost arts’ and think we should know how to do them just as a life-skill. I’ll definitely try the salsa recipe as a starting point.

    • I love learning these lost arts as well – lacto-fermentation is also very low energy since it doesn’t need cooking or sterilisation. Good luck with the salsa – it’s one of my favourites 🙂

  7. How long can you store foods this way?

    • Thanks for stopping by Sonja 🙂 I will cover the benefits of preserving food in more detail in an upcoming post, but once it has fermented, I’ve kept food in the fridge for up to a year. I live in a warm climate so do have to store them in the fridge eventually.

  8. I think I will start with the carrots! I was very surprised last year to find out that my mom has a special rock that she uses as a weight for pickling!


  1. […] posts and recipes in my head that I want to share with you, in particular one on the benefits of lacto-fermentation and one that talks about the costs of organic vs conventional food. The good news is that after […]

  2. […] If you are new to fermentation, here is a good primer from Economies of Kale: Lacto-Fermentation for Beginners […]

  3. […] Thus far our film journey has led us to many different food movements. One of these is the bubbling interest in lacto-fermentation (pun intended). We have some experience as we are both avid home yogurters, but we thought it would be fun to try fermenting in one of its other forms. While fermenting beer would be fun, we decided fermented vegetables were probably a little more appropriate to our mission. When I saw all of our mason jars laid out and ready for the veggies I was a little intimidated with thoughts of  the thorough sanitizing and precision required in canning. But, this was so easy! The whole point of fermentation is allowing the bacteria to grow so being ultra sanitary is not required. We scoured blogs for the best recipe and ended up taking advice from several. Some of those that we consulted were Daily Bites and Economies of Kale. […]

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