How to Ferment Vegetables: The Ultimate Guide
Welcome to our master guide on how to ferment vegetables. Here we are going to outline the basic process for fermenting vegetables, as well as what equipment you need, how to avoid mold, and length of fermentation time.
Before we get started, I just want to touch on the relationship between fermented vegetables and pickles.
How Fermented Vegetables are Different to Pickles
If you are a lover of all that is sour and savory, then the word ‘pickles’ might be enough to make your mouth water. ‘Fermented vegetables’ somehow don’t have quite the same ring to them! This is probably because nowadays we mostly use the term fermented to describe something in the fridge or pantry which has gone off.
Ironically, fermentation is actually a process to prevent foods from going off! During fermentation the foods which are being preserved not only retain most of their original nutrition – but also accumulate a whole new range of beneficial elements such as probiotic bacteria, naturally occurring acetic acid (one of the things that makes apple cider vinegar so healthy) and additional vitamin C and B vitamins, to name but a few.
Fermented food is what can be termed a ‘live’ food, because as opposed to dried and cooked preserved goods, fermented products are filled with living microorganisms.
Pickling is also a process of food preservation. The difference between pickling and fermenting is that when making pickles, one uses purchased acetic acid (vinegar) to use as a preserving agent for the pickles. Unless you are using raw, naturally fermented vinegar such as raw apple cider vinegar, there will be no probiotic benefits. The reason why fermentations do not need the addition of any type of vinegar, is because they produce their own acetic acid!
What more could you ask for really? Vegetables fermentation is in essence a way to make pickled anything, where the acetic acid or ‘vinegar’ appears magically of its own accord, and probiotic levels begin to develop to rival pricey, over the counter probiotic meds. In fact, while we are on the subject, according to Doctor Mercola’s lab testing, one tablespoon of sauerkraut has yielded up more probiotics than in a whole bottle of probiotics in pill form!
So without any more ado, let’s get going with our detailed guide on how to make fermented vegetables.
The Science Behind Vegetable Fermentation
Before we get into what you need to do a vegetable fermentation, and how to do one, it is important to understand the science involved in vegetable fermentation. It might sound daunting, but it is pretty simple. We cannot see the micro-organisms which do all of the good work, but we can gauge what is going on with them by how our ferment looks, smells and tastes. By understanding how the microbes work and what they need, we can manipulate their environment to ensure that they can get their good work done.
Fermentation: A battle between ‘good’ and ‘bad’ bacteria
The natural path for vegetable matter, once harvested, is to eventually degrade back into organic matter. This process is facilitated by a certain set of microbes. Besides these microbes, there are also another set which are able to live off of the vegetables and produce lactic acid to preserve them. These are termed the Lactobacillales or lactic acid bacteria, or as commonly referred to in fermenting circles “LABs’
When setting up a fermentation the goal is to support these LABs and provide them with the ideal environment in which to thrive and drive out any microbes which will facilitate decay.
Where the LABs Come From
So, where do these good bacteria come from? The lactic acid bacteria which start and facilitate the fermentation process are present and naturally occurring on the surface of all plants. Therefore, when you put your ferment together, they are already there, all they need is some encouragement to duplicate.
With many other fermentation such as kombucha, Jun tea, kefir, sourdough bread and yoghurt it is crucial to incorporate a ‘starter’, or culture. This is merely a small colony of the microbes required for the particular fermentation. In the case of fermented vegetables, this starter is not vital, as the lactic acid bacteria which kick start everything are already present.
Left Over Liquid From a Previous Ferment
It is a common practice however to incorporate a small amount of the juices or brine from a previous ferment into the liquid of each new ferment you make. This will inject your ferments with a guaranteed source of beneficial fermentation microbes. Sometimes when one is using vegetables which are not perfectly fresh, have been washed with chlorinated water or come into contact some other harmful chemical you might find that it takes a while for the remaining LABs to get going in the fermentation, as their numbers on the surface of the vegetables have been compromised.
Using Starter from Other LAB Ferments
The lactic acid bacteria are not only responsible for vegetable ferments, they are also the key players in other fermentation such as kefir and kombucha. If you do not have any brine from an already made ferment to use as starter, you can also use a small amount of kefir or kombucha to provide a source of LABs.
If You Have None – Don’t Worry
If you do not have any liquid from a previous ferment, and no other LAB ferments on the go to harvest from, don’t worry just go ahead. With luck all will go fine, and once the ferment is matured you will already have a source of ‘starter’ for your next one.
What You Need for Vegetable Fermentation
Vegetable fermentation is an ancient preserving process, and therefore you do not need any expensive gadgetry to start making vegetable ferments. As fermentation is a live process, there are however some important guidelines to adhere to when selecting a fermentation container, and there are some additional fermentation knickknacks which you can either go DIY on, or pick up for minimal cost. So hold you vegetables from the chopping block for now, and let’s get into the items you will need.
The Basic Equipment
Some of the items below you will probably find in your cupboards, and some of them you might want to purchase or DIY.
#1: A Fermentation Container
As it is practically the most important item, let’s start with the fermentation container. A fermentation container needs to meet certain specifics to be suitable for the fermentation process to take place in it.
Firstly, let’s have a look at which materials are suitable for fermentation containers:
Glass: Glass is a very good option for a fermentation container as it is non reactive, and you can get glass jars in a range of sizes to suit your needs. Many people use mason jars for their fermenting.
Earthenware: It is possible to use earthenware pots as fermentation vessels, but make double sure that they are covered with a food grade glaze which does not contain lead. Earthenware pots, while attractive, are not always ideal for fermenting in, as it can be difficult to seal them, and once closed up you cannot see what is going on inside as the fermentation takes place.
Metal: Metal is a no-go for fermentation containers. The reason being is that the acetic acid produced by the lactic acid bacteria can eat at the metal infinitesimally, causing miniscule amounts to enter the ferment. Metals are toxic in un-chelated form. The one exception being stainless steel, which does not react to the fermentation (and as such can be used). However, we prefer NOT to use stainless steel because it can sometimes leak an unwanted matalic taste into the veggies.
Plastic: Plastic is also not an ideal material for a fermentation container. Once reason is that in the case of plastic, again the acetic acid can cause a leaching of chemicals from the plastic into your ferment. The other reason is that as plastic is a soft material, it is apt to acquire small hairline scratches on its surface. These scratches can harbor small pockets of foreign bacteria, which if given the right conditions can colonize and interfere with your ferment.
Glass jars are a really great option for vegetable ferments. Besides being made out of a non reactive material, they are available in a wide range of sizes and usually have well fitting lids, they also have the added benefit of being translucent, which means that you can see at a glance what is going in your ferment. When using a jar, you will need to make a plan for some sort of airlock. If you are unfamiliar with airlocks, this is much simpler than it sounds – we’ll get into the different airlock options shortly.
One can also use crock pots for fermentation. As they are usually quite large, crock pots can be suitable if you want to do large batches at a time.
Traditional Crock Pots
Ordinary crock pots are pretty cheap to come by, but that is about where their attraction ends. They are difficult to seal, and almost impossible to fit an airlock onto. If you have one lying around you can give it a go, but do not be overly disappointed if you end up with a moldy ferment. It is also very difficult to tell with old crock pots whether or not their glazing is food grade and lead free.
Fermentation Crock Pots
Available nowadays are crock pots which are specifically designed for vegetable fermentation. These crock pots work well, are attractive, and do not need to be fitted with airlocks as they have a water seal around their rims. The downsides to fermentation crock pots are that they are expensive, and being made out of ceramic or earthenware you cannot see inside without opening the top and allowing unwanted oxygen through. Their size can also be a little impractical if you prefer doing small batches of veg at a time. Still, many people swear by these containers as the best way to make fermented veggies, especially sauerkraut and kimchi, both of which are traditionally fermented in earthenware crock containers.
Although the term ‘airlock’ might sound daunting if you are unfamiliar with them, they are very simple contraptions. Besides being simple to fit and use, airlocks also play a big role in guaranteeing that your ferment comes out superb each time, with no mold and according to the fundees, a higher level of probiotics present. In addition they are also time saving, and reduce any explosion hazards by 100% if clean and free of blockages. For the average fermenter, airlock containers are the easiest method of making trouble-free fermented veggies. Even better, airlocks are quite affordable, costing only a tiny bit more than regular glass containers.
How Airlocks Work
Airlocks are designed to release pressure buildups without allowing oxygen to flow into you fermentation container. They function much the same as a one way valve.
Why Airlocks are Important
During fermentation, carbon dioxide is produced. Pressure starts to build up the in fermentation vessel. At some point this pressure must be released, otherwise there is a danger that your fermentation vessel will explode. Not only is this a huge mess and a loss of your ferment, but it is also very hazardous if anyone is in the vicinity of the container.
It is possible to do a fermentation without an airlock, however this means that you will have to crack the lid of your ferment on a daily basis. Doing so will allow fresh oxygen in. This is not ideal, as it can cause the development of mold. It is best to keep as little new oxygen from reaching your fermenting vegetables as possible, to guarantee the best results.
Types of Airlocks
For the small cost of purchasing an airlock for your ferments, it is definitely worth the investment. Let’s have a look at what is available.
Mountable airlocks are used extensively in home brewing and other types of fermentation. They are easy to get hold of and pretty cheap. The only downside to these types of airlocks is that you will have to mount them yourself onto the lid of you jar. This will involve drilling a hole and securing the bottom tube with its bung into the hole. Not a big deal if you have a garage full of tools, but a bit of a pain if your tool box consists of an old kitchen knife and rusty screw driver!
Pickles pipes are a really convenient and simple type of airlock, engineered especially for vegetable ferments. They have one constraint and that is that they are made to fit into the tops of Mason jars, and aren’t really suitable for other types of containers. However the fact that they are intended to fit into the tops of Mason jars also makes them a super convenient option if you are thinking of going the Mason jar route. No drilling or fitting into place, they are ready to go. Their simple design also makes them very easy and quick to clean. As they do not use water for the seal, this makes them maintenance free in that you do not need to top up the water as with standard airlocks and fermentation crock pots (which also have a water seal).
Container with Ready-to-go Lid and Airlock
It is also possible to pick up containers which have airlocks already attached to their lids. If you are buying one of these, just make sure that the container is not made out of plastic.
It is difficult to say what the across the board best option is, as this will depend on your needs. If you intend to make large batches of fermented vegetables at a time, and therefore are looking for a large vessel – then it will probably be best to go with a mountable airlock which can be fitted onto the lid of a big glass jar. If you are looking at a fermentation crock pot for your large ferments, then purchasing an airlock is not necessary as it has its own airlock system in the rim. If however you are looking to do smaller batches at a time, then using mason jars in combination with pickle pipes is a convenient way to go. You can get the mason jars and pickle pipes in a variety of sizes, they fit together seamlessly, no mounting of airlocks required, and the airlocks are maintenance free during fermentation and super easy to clean afterwards.
That said, if you have a whole bunch of jars which you are planning to put to use as fermentation containers by fitting airlocks into the tops – by all means do so!
#2: Weight to Keep the Vegetables Submerged
Once you bottle up your vegetables, what tends to happen is that their natural buoyancy causes some pieces or parts of the vegetables to rise about the surface of the brine which they are supposed to ferment in. Because they are now out of the salt water and in contact with oxygen, these surfaces can become moldy. Mold is not something which you want in your fermenting vegetables. This is why it is a good practice to place some kind of a weight on the top of your vegetables to keep them submerged before you seal up your ferment.
Here are some options:
Have a look in your kitchen. You should be able to find an object such as a small plate, bowl or saucer which can fit snugly on top of your vegetables and weigh them down. Just remember not to use anything which is made out of plastic or metal.
If you do not feel like hunting around trying to find something to fit each jar which you want to use for your vegetable ferments, then pickle pebbles are a good option. They come in a variety of sizes, are designed to keep your ingredients submerged, and are reasonably priced.
It is not vital to keep a thermometer, as it is not directly involved in the fermentation process. However, it can be interesting to keep a thermometer next to your fermenting vegetables to see how the ambient temperature where they are affects the rate at which fermentation takes place. Knowing at what temperature they are fermenting can also assist you to decide when to stop the ferment.
Water Filter (optional)
It is very important they you do not use chlorinated water for your ferments. The chlorine can kill the naturally occurring lactic acid bacteria on the surface of the vegetable, and this can result in a failed ferment. If you do not have a source of un-chlorinated water, such as rain water, then it might be a good idea to invest in a filter for home use.
The simplest and cheapest option is one of those jug filters which sit on the counter or in the fridge. They are inexpensive and simple to use. While their filters are not always of the highest quality, one can circumvent this by letting the full jug sit overnight to let any residual chlorine or other chemicals evaporate off. The other alternative is to boil before putting it in the jug, for about 10+ minutes to get a good amount to evaporate off first.
Faucet Fitted Filter
Fitting a filter to your faucet is a great way to filter out harmful chemicals, not just for ferments, but for drinking and cooking as well. If you only require filtered water for your ferments however, then getting one of these might be an unnecessary expense and you could be better off with a jug filter.
Fermentation Diary (optional)
For those of us who like to fly in the kitchen by the seat of our pants and scoff at things like measuring cups and scales (found guilty), then the thought of keeping a fermentation diary sounds terrible. But if you like to tackle your kitchen projects like a science, and let’s be honest, that is what fermentation is about, then keeping a fermentation diary can be interesting, and useful for later reference.
It does not have to be anything complicated, merely a notebook, or a set of calendar entries on your tablet or phone, stating when you started the ferment, the ingredients, and how long it took to mature. If you have a thermometer you can enter the temps as well.
Other Basic Kitchen Equipment
Besides the fermentation items, you will of course need some basic kitchen utensils.
- Kitchen knife for chopping vegetables
- Chopping board
- Grater if your want to shred or grate vegetables
- A couple of bowls
Besides the basic equipment which one needs for fermenting vegetables, there are of course also the ingredients!
You are going to need some vegetables. One can ferment almost anything, but here are some ideas to get you going:
- Chinese cabbage
- Green beans
Besides vegetables, you can also add herbs and spices for extra flavorings:
- Pepper corns
- Bay leaves
- Mustard seeds
If you do feel like thinking of what herbs or spices to add, you can also just pick up a packet or regular pickling spice which will usually contain a combination of peppercorns, mustard seeds, and bay leaves.
You can do an absolute basic ferment with nothing but a single vegetable + salt, sans spices, herbs or anything else. And you can get something divine. One example of this is your basic sauerkraut recipe, which is simply cabbage and salt! Of course, there are many variations where you can add extra ingredients. So you can really combine ANYTHING to ferment — different types of veggies, spices, and herbs. You can even ferment fruit, not just vegetables
As mentioned above, it is very important that you use un-chlorinate water for the brine for your ferments, and for washing the vegetables with beforehand. If you do not have a source of unfiltered water, or a filter to purify it, then you can pick up a couple bottles at your local store.
You will also need some non-iodized sea salt to make the brine which the vegetables will sit in. My recommendation here is celtic sea salt or himalayan salt for the best quality, best tasting salt.
How to Do a Basic Vegetable Fermentation
Once you have assembled your fermentation equipment and ingredients, you will be ready to put your fermentation together.
There are literally thousands of different fermented vegetables recipes, kimchi alone boasts over 180 traditional variations! Here we are not going to use a specific recipe, but rather provide you with step by step guide to give an overview of the process of vegetable fermentation.
The Two Salt Techniques: Brine Versus No Brine
Before we start, there are two different techniques with regards to the salt.
The Brine Method
Some recipes call for a brine to be made, which is poured over the vegetables which are packed into the jar, until the jar is full. This method is best used for chunky or hard vegetables, such as carrot sticks, asparagus sticks, gherkins or pickled onions. Note, brine is simply water mixed with salt.
The Salt Rub Method
The other method is to combine the chopped vegetables and coarse salt in a bowl, and leave to stand, rubbing the salt into the vegetables every now and again. The idea behind this is that the salt draws the juices out of the vegetables and when transferred to the fermentation vessel they will ferment in their own juices.
This technique is good to use when you are going to be fermenting leafy vegetables such as spinach or cabbage, grated vegetables or pureed vegetables. Between the two ferments, I find the salt rub makes a better ferment that’s fresher and more crispy. But sometimes, you might need to choose the other method for larger vegetables.
Which Method Is Better?
A good rule of thumb when trying to decide which method to use is to ask yourself ‘Do I want brine, or not?’ If you want to have vegetables in brine, then go for the brine method. If you are doing something like sauerkraut or kimchi, where excess water is not needed, then use the salt rub method. For those fancier ferments where you mix in a lot of vegetables with moist or dry spices, you’ll want the salt rub method, else you’ll end up with a liquid!
For this guide we are not going to specify quantities, as that is entirely up to you. Just make sure that you have a large enough fermentation vessel for your ingredients, or the other way round – merely chop the right amount of vegetables to tightly fill your fermentation container. As long as you stick to the brine recipe, and make sure that the brine covers the top of the vegetables when you are done, all will be fine.
Chopping Up Your Veggies
The most time consuming part of your fermentation (besides the actual waitin for the ferment to finish), is chopping up the veggies. This can take anywhere from 10 minutes to an hour, depending on the amount.
Personally, I hate this part. It’s boring, time consuming, and the part I detest the most. You might like chopping veggies for half an hour, but for those who don’t want to do this, you can buy a few items that make this easier.
For harder, leafy veggies, you use this god-send of a machine to slice up the vegetables into fine strips. Fantastic for sauerkraut and other ferments where you need finely chopped up veggies. You can slice up an entire cabbage in a minute or two!
This dices hard veggies (cabbage, carrots, beets, etc) into fine little spirals. You can also adjust the settings so it does regular strips. This makes dicing and slicing BIG items (like really big cabbages, pumpkins, etc) quick. For real mass production, I recommend this item.
Step 1: Assemble Your Items
Assemble the following:
- Your vegetables
- Non-iodated sea salt
- Un-chlorinated water
- Kitchen items
- Fermentation vessel
Step 2: Wash your fermentation vessel
Give your fermentation vessel a wash with some warm water and spirit vinegar. Never use antibacterial soap, as residues could stay behind and hinder the fermentation.
Step 3: Rinse and chop your veg
Take the vegetables which you will be fermenting and give them a rinse in some un chlorinated water. Set aside and let drip for a moment. Again, if you don’t want to spend the manual labor chopping up the veggies, use a Cabbage Mandoline or Food Spiralator to do in 5 minutes what would take you 40.
Step 4: Make the brine
Now take a jug or another bowl, and mix in salt and water to the ratio of 2 tablespoons salt : 1 quart of water. You can decrease or increase this ratio slightly, to your taste or preferences. Just remember that the less salt you use, the high the chance of mold. If you do not like salt, and want to use as little as possible, then make 100% sure that you use an airlock and a weight to keep the vegetables submerged during fermentation, to compensate for any heightened risk of mold.
Step 5: Pack and pour
Now take your chopped vegetables and pack them into your fermentation vessel. Once almost full press them down so that they compact, and then pour in the brine until it covers the top of the vegetables. There should be one inch space between the surface and the lid, no more.
Step 6: Add Starter
If you have any starter liquid, you can add this now.
Step 7: Seal Up
Place your pickle pebble or other type of weight on top of the vegetables to weigh them down, and screw on your lid!
Step 8: Leave to ferment
Place your sealed up ferment in a place which is room temperature, and out of direct sunlight. If you have other ferments going on like kefir, kombucha, Jun tea or yoghurt, then make sure that you keep your new vegetable ferment at a distance from any of these. It is important to maintain a distance of about 4 feet between ferments, as they can ‘cross-pollinate’ with each other’s bacteria. This will results in contaminated cultures and ferments whose bacterial balance is out of sink, and you will probably experience a decline in the quality of your fermentations.
Step 9: Time the ferment
The time which you should leave the vegetables to ferment is dependent on how tart you want them to be, and what the temperature is in your house. Most vegetable ferments done in an ambient temperature home should be left for a minimum of 1 week. However you can leave it for a much longer time than this, such as three weeks. If the temperatures are low, some ferments can take as long as 6 months!
Fermentation time and temperature –
To give you a basic guideline, here is a rough idea of the average fermentation time at different temperature ranges:
- 50-60o Fahrenheit (10-15o Celsius) : Up to 6 months
- 60-70o Fahrenheit (15-20o Celsius) : 2-6 weeks
- +70o Fahrenheit (+20o Celsius) : 1-2 weeks
Experts say that the longer you leave your vegetables to culture, the higher the probiotic count will be. It is thought long, slow ferments at low temperatures develop the most complex and beneficial complement of bacteria. For some traditional recipes (sauerkraut and kimchi), months of fermentation are sometimes utilized to deliver precise flavors.
However it is important that you enjoy the product of your labors, so if you prefer fermented vegetables crispy and not too tart, then you can achieve this by stopping your ferments earlier rather than later. You can enjoy fermented veggies in as little as a week if you don’t want to wait. And if you are NEW to fermenting veggies, we recommend you first try out shorter ferments (1 week to 2 weeks) first, before going down the road of long fermentation times.
Step 9: Stop the ferment
When it is time to stop the ferment, all that you need to do is to transfer it to the fridge. Any airlocks can be removed at this point, as the cold temperatures of the fridge will be enough to stall fermentation so as to not allow any more pressure to build up. If your fermentation vessel is not suitable for going into the fridge, such as a fermentation crock pot, or very large glass jar, then you can decant the fermented vegetables into smaller jars and seal up by screwing on the lids.
How Long to Keep Fermented Vegetables
Fermented vegetables can keep for ages in the fridge. However once you open a jar and start consuming them, try to finish them up within a month. If you see any mold starting, then discard the contents of the jar.
Make sure that you always use a clean spoon when dishing out the vegetables, and do not eat them straight from the jar – no double dipping! This will lengthen the time which your fermented vegetables will keep once opened.
What Can Go Wrong
If the bacteria are given the right conditions to multiply and oust out the unwanted ones which facilitate decomposition, then your fermentation should take place without any mishaps. However every now and again things do not go according to plan, and you will have to evaluate what might be causing this.
As mentioned under the airlock section, mold is one of these mishaps which can occur.If you find mold developing in your ferment, you can scrape it off and you won’t be the worse for wear. Mold only develops in the top.
There is some debate about whether the mold is harmless, but common word is that it is. I personally just scrape it off.
However, one issue with mold (depending on if you have a brine liquid or no brine to seal out the mold from going beyond the surface) is that mold can take roots that are not visible to the naked eye, which means that even if there is a very small amount of mold on the surface of your vegetables, there could be roots through a larger portion of it.
Again, for most people, scrapping off mold from the top is fine.
How to Avoid Mold
1. Use a mold-preventing container
You can avoid mold completely by using a fermentation crock (with the stone weight) or a fermentation airlock. Or by using a regular glass jar with a weight to keep the fermented veggies beneath the surface of the brine so it’s not touching the air.
2. Check you equipment:
- Lid & airlock: Make sure that the lid is sealing properly, and the airlock is not blocked. If you are not using an airlock, and burping the ferment to release pressure – then you should get an airlock.
- Brine & Salt: Make sure that you are using an adequate amount of salt. You can increase the salt slightly if this will not make your ferment too salty. Also check that whatever you are using to keep the vegetables submerged is doing so properly, and nothing is sticking out of the brine. If you are not using a weight or pickle pebble, then start using one.
Lack of Fermentation
What can also happen when doing a fermentation is that nothing happens! This means that fermentation is not taking place. With vegetable ferments this will manifest as an absence of carbon dioxide build up, and tartness. Here are some possible reasons and what to do.
What to do:
If fermentation does not seem to be taking place, check the following.
Temperature: If the temperature is under 50 o Fahrenheit (10 o Celsius), or even 60o Fahrenheit (15o Celsius), then you might find that fermentation is taking place, it is just doing so at a very slow pace. Which is not a bad thing! So keep patient, and give it time.
Lactic Acid Bacteria: If there does not seem to be any sign of fermentation taking place, and the temperature is warm enough for it to be happening relatively quickly, then the lactic acid bacteria might have been compromised. Using chlorinated water for brine, or washing one’s vegetables in it can contribute to this, or using detergent based dishwashing liquid on your fermentation equipment. Perhaps your vegetables had been sanitized prior to you purchasing them, and the lactic acid bacteria on their surface had been killed.
To make sure that there are enough lactic acid bacteria to get things going, find a source of starter liquid.
You can use this guide to ferment your own combination of ingredients, or you can use it to give you an understanding of other vegetable fermentation recipes. Having an overall knowledge of how fermentation works can allow you to tweak things to suit your ingredients and needs, while mold, and still getting the best results and preserved vegetables which are exactly the way you like them – whether that is crispy and mild, or extra tangy and rich in probiotics.
Fermented vegetable are a great way to incorporate a potent source of probiotics into your diet. They make a great addition to soups, stew, salads sandwiches and snack platters, and can even be gobbled up on their own!
If you are someone who hates having food go to waste, fermentation can be a great way to use up vegetables in your fridge or pantry which you are not going to be able to cook before they go off. If you have a vegetable garden, vegetable fermentation can also be the perfect way to preserve a harvested crop of something which you have in excess.