How to Preserve Vegetables using Self-caught Cultures

All Photos by David Ashwanden

With the current global food system being the vast network of producers, suppliers and consumers that it is, sometimes ideas of preserving food may seem a little irrelevant. Before planes, lorries and fridges became so prevalent, if you wanted carrots any time other than carrot season then you either had to wait, or you had to somehow capture that carroty goodness in a way that meant that you could still eat it weeks or even months later.

Why would you wish to preserve it, though, when you can simply walk to your nearest supermarket for year-round carrot availability?

A Carroty Question

A Carroty Question


Reasons to be preservative

For me, the reasons for food preservation are numerous, and effect and are affected by not just the food but all that is going on around me in my life. For example, it is not just my own body that I am affecting when I buy food. As mentioned in my ‘The Simple Art of Lacto-Fermentation: An Introduction, when we buy food which is imported, we are engaging in a complex web of energy which we may never be fully able to calculate, but which we can pretty much guarantee has contributed to extra carbon emissions being added to our atmosphere. For example, the Food Climate Research Network estimates that in the UK alone, 19 million tonnes of carbon are released into the atmosphere from our food industry and transport; 40% of this comes from current agricultural methods (1).

                If you feel that we need to decrease the amount of carbon released into the atmosphere, the action you can take to facilitate this can be as simple as changing what you eat.

As someone keen to put into practical reality the transitions which are necessary to ensure a sustainable future of abundance, I decided to limit the amount of food I eat which is imported and instead preserve food when it is in season so that I can enjoy its freshness all year round.

Keeping food fresh

                A simple way to prolong your food’s shelf-life is to put it in the freezer; but this will mean it loses nutrients. You could also heat it up to a very high temperature and can it; again, nutrients are lost in this process, and both of these methods are quite energy-intensive. Luckily, people have been preserving food for much longer than freezers or sterilisation has existed, and there are many other low-impact methods. For more details, I can recommend Claude Aubert’s Keeping Food Fresh: Old World Techniques and Recipes (2).

Lacto-fermentation does not involve heating your produce to high temperatures, or indeed cooking it at all, and neither does it involve cooling techniques or sterilisation. All of these methods have been developed in order to kill bacteria, but the whole point with lacto-fermented foods is that you are getting the beneficial bacteria to work for you. In this way, lacto-fermentation very neatly turns the problem of bacteria which could make food unsafe to eat into the solution of utilising it to create a tasty and nutritious preserve. You may not have heard of lacto-fermentation before, but you have probably heard of sauerkraut and kimchi – both of these are lacto-fermentated foods.

Yes, not only does this method of preservation keep pretty much all of the nutrients from the vegetables you are preserving, but the very act of preserving actually adds nutrients. The presence of lactobacillus and other bacteria in the same family help aid digestion and are a significant source of vitamin C and protein (see for example 3, though if anyone can find a more exact nutritional analysis I’d be very interested to know it!).


                So now you know some of the reasons why you might want to lacto-ferment, and some of the benefits it can give to not only you, but the entire planet. Presumably, your appetite has been whetted; so what comes next should be a recipe. However, I am reluctant to term my skill-sharing as such, as the word ‘recipe’ implies a set amount of ingredients, a strict method and a limited amount of things you can use. Yet the joy of lacto-fermentation is that (as far as I have found) the only limit is your imagination. What I am going to share with you, then, is more like a set of simple guidelines; starting points and advice from which you can make a springboard towards your own fermexperiments.

Some loose steps to follow

  1. Getting started

First, you need to choose what you are going to lacto-ferment. I have tried a vast number of fresh foods, the majority with a high degree of success. Vegetables are what I have the most experience with so I am going to share my vegetable method with you here. You can also lacto-ferment fruit, or even combine this method preservation with another low-impact, high nutrient saving one: that of drying. For more information on this, you could try visiting Annie Levy’s fantastically inspiring blog here(4).

As it is October in the UK there are still quite a lot of locally-grown carrots and beetroots available, so these are what I chose for my example ferment.

  1. Veg preparation

I washed all the veg I was going to use, which ended up being one and half carrots and half a beetroot for one medium-sized jar. Then I peeled the beetroot as it was a big one and the skin was quite thick. If you are using non-organically grown beetroot then you may prefer to do this, as the chemical residues are thickest in the skin (5), though the fermentation will still work even if you do not.

Peeling the Beetroot

Peeling the Beetroot


                Now you can choose how you are going to cut up your vegetable. There are many ways to do this – as many ways as you can think of to make things smaller, really. Some traditional recipes call for a particular way of cutting; for example, in most sauerkraut and kimchi recipes I have found they say to shred the cabbage before fermenting it (see for example 2). You can also chop your veg into cubes, strips or chunks, however; I have found that the choice is really down to your own personal preferences.

The key to deciding what to do with your veg is knowing what conditions it needs to be kept in. in order for the correct bacteria to colonise you need it to be moist, and in order that the wrong bacteria (that which could be detrimental to your health) does not inhabit your vegetables, you need to make sure they stay covered with both salt and water. In ensuring this, your chance of success will be greatly enhanced if you pack the vegetables tightly into your chosen container, in whichever form you choose to cut them into.

The reason for this is so that you can make sure that your food stays covered with the water and salt: if it gets exposed to the air, then it is no longer part of the preservation process and the normal process of air-exposed fresh food, i.e. rotting, will begin. You want your veg to stay nicely preserved so squeeze it in tightly!

With all of this in mind, I decided to make my example lacto-ferment using grating. After washing them and peeling the beetroot I used a grater to make them into very small pieces.

Grating the veg

Grating the veg

  1. Packing it in

I then picked up the grated carrot a handful at a time and, taking my clean (but not sterilised) glass jar, I covered the bottom of it in a layer.

Putting the carrot in

Putting the carrot in


                Now comes the important part: having placed the carrot into the jar, I pushed it down to make sure it squashes in really tightly. I have found that using fingers here is fine, as long as they are clean; the whole point of the lacto-ferment adventure is to create an environment where any bacteria except the ones you want will perish.




  1. Fill it up

As I had carrot and beetroot to ferment I decided to pack them into the jar in layers. This is more of an aesthetic thing than anything else, though it is good to be conscious of what order you will feel like eating things when you come to open your fermenting jar. If you are preserving two different vegetables, are you happy to only have access to one at a time? Or do you wish to mix them up in the jar so that when you open it you have an immediate variety of flavours?

To some extent whatever you put together in the jar will give its flavour to the whole mix anyway; this is especially true with very strong-flavoured foods. With this in mind I added a little bit of chopped garlic to the jar. Though only about one clove, it will end up imparting a delicious pickled-garlicky taste to the entire ferment.

Preparing the garlic

Preparing the garlic

Adding the garlic

Adding the garlic

                Then I made sure I packed the jar full with the rest of the carrot and beetroot.

                It is very important that you do not fill the jar to the brim. Firstly, you are going to add water, so there needs to be enough space for the water to come in. Secondly, during the fermentation process your mix will expand so it needs the volume to do this. Thirdly, if the mix ends up touching the lid of the jar it could become exposed to air and thus contaminated.

                This is about the right level.

Good level

  1. Just add water…

Now you can carefully pour in enough water to cover the veg mix. When I first learned about lacto-fermentation during my PDC with Tree-Yo at Permaship, Bulgaria, I was advised to use spring water with all ferments if at all possible. Indeed, many sources insist that if you use tap-water the fermentation may not work at all (see for example 6). For about a year I followed this strictly, which was not difficult as at the time I lived on a mountain-side and all of our water came from springs. However, when confronted once more with chlorinated tap water I decided to continue my experiments anyway, and have found no marked difference between texture, taste, or length of time for fermentation when using tap water.*

*The tap water I used came from mains water in the South of England. Many chemicals are added to this water to treat it but not as many as in other countries such as the USA and Australia, so readers from these countries may want to find alternative water sources.

  1. …And salt

This step is really what differentiates your lacto-ferment as a preserve rather than just some vegetables in a jar; that magical ingredient of salt. For a medium sized jar (the jar I am using in the pictures originally held 454g of honey) you do not need more than 1 teaspoon of salt. You probably need even less than a teaspoon but this is the measurement that I have found is safe and effective. Place the salt into the jar with the vegetables and water.

  1. Shaking with excitement

In order to mix the ingredients thoroughly and ensure that the salt and water is covering all parts of the vegetables, it is probably a good idea to close the lid of the jar tightly and shake it up.

Serious shaking

Serious shaking


  1. Get ready to catch some culture

The idea of lacto-fermentation is that even though all you have put in your jar so far is water, salt and vegetables, you will be using this bait to catch some bacteria culture which will preserve the veg for you. In order to do this you need to leave the bacteria a way to get in. However, you don’t want anything that isn’t a kind of lactobacilli colonising your beautiful preserve, so you need to make sure that the vegetables are packed in tight and completely covered with water.

I usually place the lid of the jar loosely on top of it without screwing it closed, and then leave the jar in an out-of-the-way place for two or three days in order to catch the bacteria.

It is also a good idea to put the jar on a plate, as once the fermentation process begins it can potentially become quite volatile and subsequently messy.

In warmer weather the colonisation will be quicker so if it is winter and you never turn the heating on in your kitchen, don’t worry if there is no sign of bacteria after a couple of days. Keep waiting; it will probably turn up.

  1. Recognising your new friend

You can tell when the culture has arrived in your jar in a number of ways. One is if you lift the lid of the jar to find that it is fizzing. No need to run away here – this is a perfect sign that you have successfully caught some bacteria. Another is to look into the jar to see if there is a milk-like residue. This is the culture itself inhabiting the new home you have made for them; again, a very good sign.

A New Culture is Here!

A New Culture is Here!

                Once you have captured your bacteria (giving a whole new meaning to the idea of reviving hunter-gatherer techniques), you can close the jar’s lid fully to seal it. This is not a necessary step as the lacto-ferment does not need to be airtight; however, as mentioned above in step 4, you do need to ensure that the veg are completely covered with water at all times and so if you are going to put the jar in storage, one of the easiest ways I have found is to simply screw the lid on and put it away; remembering to label it, of course.

                Before packing it into your cupboards, it may be a good idea to keep the jar out with the lid on for a few more days, just to check on the fermentation process and make sure that everything is fitting alright.

When I came back to mine four days later I found this:

ferment explosion

ferment explosion

                What had happened was that the fermentation was so vigorous that there wasn’t enough space for it in the jar. This does not always occur, and I have found it is more common with foods with a higher sugar content, such as carrot and beetroot. When lacto-fermenting less sugary foods such as celery and cucumber the ferments are generally much better behaved.

If this happens to your ferment, simply take out the excess vegetables, which will probably be tasty and good to eat, as long as they have not been exposed to the air for too long. Then re-pack what’s in the jar and re-fill it with water. You will probably also need to wash the lid of the jar before replacing it.

10. Using the cultures as Mothers

If you have already lacto-fermented something previously, you can skip step 8 because you already have the bacteria culture captured. All you need to do is take a teaspoon of the liquid from a previously opened lacto-ferment, and add it to your newest batch along with the water and salt. Then you can simply close the jar immediately, because you have colonised the jar using your own Mother Bacteria.

Adding the mother 1

Adding the Mother

Adding the Mother


  1. Fermenting Frenzy

Congratulations on your fermenting. Now that you have joined me on this preserving adventure, I’m sure you will be brimming with ideas for the next one. What will you ferment now? Whatever it is, remember to always use your sensitivity when preparing food in this way. For some people the taste, smell and volatile fizziness of a lacto-fermented food may seem so alien that it at first cannot be trusted as edible. But your body knows what’s good for it, as long as you listen to it. Anytime you are not sure about whether or not it is safe to eat some food which you’ve had a go at preserving, it’s probably best to leave it alone. At the same time, the more of a feel you gain for this kind of thing, the more your confidence will grow, so just keep trying.



  1. Climate Choices, 2014. ‘Food Miles and carbon Dioxide’. – retrieved 17/10/14
  2. Aubert, C, 1999. Keeping Food Fresh: Old World Techniques and Recipes. Chelsea Green: London
  3. Livestrong, 2014. ‘What are the benefits of raw sauerkraut?’ – – retrieved 17/10/14
  4. Kitchen Counter-Culture, 2014. retrieved 17/10/14
  5. Dellorto, D, 2014. ‘Dirty Dozen produce carries more pesticide residue, group says’. CNN, 2014. 17/10/14
  6. Meredith, L, 2014. ‘Lacto-fermented Carrot Recipe’. retrieved 17/10/14

4 thoughts on “How to Preserve Vegetables using Self-caught Cultures

  1. Rob FIrth

    I don’t know if i perhaps missed it , but once you have closed the lid (after the bacteria has arrived 🙂 ) is there a minimum time you should wait ? can you open the jar along the process to check it or should you just leave it and let it do its thing for a couple weeks, months? Im guessing you can leave it for as long as you like (hence preserving) . Thanks.


    1. Charlotte Post author

      Hi Rob! THanks for your comment. From my experience, it is worth waiting around 2 – 3 weeks for the flavour to really imbue the whole jar. And yes it’s fine to open the jar occasionally to check it – indeed, this may be recommended as the ferment may need to ‘burp’ to release the excess gas. Just make sure that if you use any implements once it’s open, they are clean, and that you cover the whole mixture with water again before closing it once more. Happy fermenting!


      1. Rob FIrth

        Ohhh, the excitement that followed after realising the culture has been captured… another question however . after 3 or 4 days when I’ve really let the culture build up , do I then a) shake it up before storing it (The reason I ask this because having that white culture everywhere on the top doesn’t look very good , especially if I’m offering it to friends and family.). And B) can I store it in the cupboard to ferment and then like you say 3 weeks plus move it to the fridge or just leave it in the cupboard ?

        Thanks again 🙂


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