HOW DOES LACTO-FERMENTATION WORK?
So, how does it work? A brine is created by adding salt to vegetables which release their juices, or by dissolving salt in water. The vegetables are submerged under the salty brine, in an anaerobic (no oxygen) environment, so any microbes which spoil food, or those which can cause foodborne illness, cannot survive.
Lactic Acid bacteria (LAB) are naturally present on the vegetables, and they can tolerate and survive in the salty, anaerobic conditions. The LAB feed off the sugars in the vegetables, convert it to lactic acid, which lowers the pH to create an acidic environment, which safely preserves the food. The LAB are the good bacteria, commonly known as ‘probiotics’.
WHAT CAN YOU LACTO-FERMENT?
You can lacto-ferment a number of foods, including:
- vegetables (like cucumbers, cabbage, carrot, beans, garlic)
- salsas, sauces and other condiments
- dairy (yoghurt and cheese)
- fruit (lacto-fermenting fruit may be more complicated)
This guide covers the essentials about lacto-fermenting vegetables, as that is a great place for beginner’s to start.
Note, there are other types of fermented or ‘cultured food’, such as sourdough, vinegars, beer and wine, kefirs and kombuchas, cured meats etc. which use different microbes.
DOES LACTO-FERMENTATION INVOLVE LACTOSE/ DAIRY?
A fairly common misconception related to the term ‘lacto’ often occurs, but ‘Lacto’ fermenting does not mean that dairy has to be involved (although you can find LABs in fermented dairy, i.e. yoghurt). It refers to the Lactobacillus lactic acid bacterias required for the process.
ADVANTAGES TO LACTO-FERMENTATION
- May increase biodiversity in gut microbiota, and improve levels of ‘good bacteria’ strains of Lactobacillus bacteria
- May include making some foods more digestible, as lacto-fermenting breaks down indigestible elements, and also increases the bioavailability of enzymes, vitamins & minerals in the food
- Easy to moderate difficulty level
- Requires less equipment and energy/ water use than other common preserving methods (i.e. bottling or dehydrating)
The collection and diversity of microorganisms (known as your microbiota) in your large intestine can affect your digestion, immunity and mood, so why wouldn’t we want to increase diversity and build numbers of the good guys?! Read more here in 10% Human by Alanna Collen. You can also read more about how the good bacteria make it to your large intestine in this article.
DISADVANTAGES TO LACTO-FERMENTATION
- The sour/ tangy/ salty taste and strong funky fermenting smells may be not to your liking
- Takes space on your kitchen bench for jars of ferments for weeks at a time, and then room in your fridge (or a suitable cool place) to store them once they have reached the level of fermentation you desire
- Requires chlorine free water, and iodine free salt (which may not be as accessible)
- Fermented foods may not last as long as bottled/ canned preserves. Whilst they can be boiling water bathed in jars, this processing/ heat treating in a boiling water bath kills off the good microbes (same reason why it isn’t recommended to heat/ cook your fermented veges, or use them in hot foods above 42°C)
- Need space to store the equipment and jars of ferments
You don’t need to start with expensive equipment, but I think it is worth researching purpose built fermenting equipment as there are many affordable options and ways to retrofit your existing preserving jars these days.
You will need:
- purpose made fermenting jars with valves in the lids (or adapt your own preserving jars by buying lids with valves that fit the jars), or fermenting crocks with lids – or you can use a large glass or ceramic container (called open vessel) like Mason jars – avoid metal containers (it may react with the acid)
- something to weigh down the vegetables under the brine, like a smaller jar that fits into the mouth of the container, or a small ziplock bag of brine, a glass weight, or a piece of cabbage to wedge into the container
- tea towel/ cover to wrap around glass containers, knives or mandolin for cutting finely, measuring spoons, scale for weighing salt, jug & whisk to dissolve salt into brine, tool for pounding (when making sauerkaut) – Metal utensils to make the lacto-ferment are OK.
- Use organic vegetables to make sure you have good Lactic Acid Bacteria (LAB) where possible
- Use water without chlorine – we have a stoneware water purifier with a filter that removes fluoride and chlorine from our tap water
- Fine table/ cooking salts are suitable to lacto-ferment with, providing they have no iodine added. The iodine has antimicrobial properties, and could affect the development of our LAB/ good bacteria. Also check there are no other additives, like anti-caking agents.
HOW MUCH SALT DO WE USE?
You need a brine between 2% up to 10%. Too little salt and you are at risk of the bad bacteria growing. If you use too much salt, instead of lacto-fermenting, you may actually be ‘salt preserving’, which isn’t necessarily bad, you just miss the good microbes and may also end up with a product too salty to eat!
The more salt you use, the slower the fermentation will be, and the sourer (more acidic) the end result will be. The less salt you use, the faster fermentation will be, and less sour result.
DRY BRINE (AKA SELF BRINE)
We can create a Dry Brine by adding salt to vegetables (such as cabbage when making sauerkraut, AKA a ‘self brine’) and massaging and pounding it in, causing the juices from the vegetable to be released (from osmosis and as the cell walls breaks down) and mix with the salt.
- The general ratio is 1 tablespoon (17gm) of salt for every kilogram of vegetables.
We can create a Wet Brine by dissolving salt in water and create a brine to pour over vegetables (such as cucumbers, when making dilly pickles).
- For every tablespoon of salt, 17gm, you add to that litre of water, increases the brine by approximately 1.8% (see note)
- To make a 3.6% brine, use 2 tablespoons (34gm) per litre of water. If you are fermenting in cooler weather or conditions, or fermenting harder vegetables (i.e. carrots, green beans, beetroots) you may use a lower brine, like 3.6% brine. This is considered ‘half sour’ when fermenting cucumber pickles.
- For a 5.4% brine, use 3 tablespoons (51gm) per litre of water. If you are fermenting in warmer weather, or using higher water content vegetables (i.e. cucumbers) consider using a higher percentage brine, like 5.4%, which will help control the ferment and retain crunch. This is ‘full sour’ when fermenting cucumber pickles.
How do we eat lacto-fermented veges?
You can eat them as a condiment, on top of breakfast, lunch or dinner! They will lose their good microbial benefits if you cook them, or expose them to hot foods. I eat mine with my veges and fried egg for breakfast. I love them in a salad wrap. I plonk some of top of a curry or soup before eating.
Start slow with the amount that you consume, building up over time, as you may experience ‘die off’ (of all the bad bacteria built up in your gut) when starting out with cultured/ fermented foods. ‘Die off’ may be flu-like symptoms. This article explains a bit more.
STORING YOUR LACTO-FERMENTED Veges
Label, date and store your jars in a cool, dry place with temperatures between 0 to 10° C. This is likely to be your fridge, but it may be a root cellar or pantry. If you freeze them, the good bacteria may revive upon being defrosted, or may not, and the vegetables will probably go mushy anyway.
HOW LONG DO THEY LAST?
It depends on many factors, like what vegetables you fermented, how sour you like it, if it has gone too soft/ mushy etc. Some people store their lacto-fermented vegetables for months, even eating them after a year. I generally eat mine up within a couple of months after being moved to cold storage, but I then I purposely make smaller batches so that they don’t linger in the fridge for months.
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