Fermenting is an ancient process, so engrained in our quotidian routines you probably engage with it multiple times every day without knowing it. Coffee, chocolate, and olives are just a few examples.
In its entirety, it’s a subject that breaks down into a mind-boggling number of subcategories and sub-subjects, with every new door you open leading to a room of 10 more doors. To weaken the dizzyingly humbling curve of the Dunning-Kruger effect, we’re going to focus on a common microsection that produces wondrous results and can be done at home. Bubbly, acidic, and oozing with umami, read on for lacto-fermentation.
What is lacto-fermentation?
It’s a method of food preservation where naturally occurring bacterium, Lactobacillus, converts sugars into lactic acid. Lactobacilli are a beneficial and probiotic bacteria, and as they multiply and produce more lactic acid, they – in combination with additional salt – create an environment that inhibits the growth of harmful bacteria and microbes, extending the fermenting food’s shelf life. Lacto-fermentation is anaerobic, so for it to work the environment needs to be oxygen free. The resulting food is tangy, umami-rich, and packed with probiotics.
Dry vs. wet lacto-fermentation
Dry fermentation follows the same process as dry brining. It’s best used for vegetables with a high water content, or those that are chopped up or grated. Common examples of dry fermentation foods are kimchi or sauerkraut. Start by weighing the chopped vegetables you’re fermenting and add 2% of that weight in salt (a sum to achieve this = combined weight x 0.02). Massage the salt into the vegetables until a brine is formed from the juices. Pour this mixture into a sterilised jar and press the solids down until they’re underneath the waterline. You can use a weight to keep the solids within the liquid (the oxygen free environment) before sealing the lid. Store the jar in a cool, dark place, like your pantry, for at least a week before moving it to the fridge; we find that two weeks is a good amount of time for a delicious tangy flavour to develop.
During fermentation, lactobacillus also produces carbon dioxide. To release this gas build up, ‘burp’ it every morning and night by opening then closing the lid. If you don’t burp your sealed ferments, they will explode.
For wet fermentation, you create the brine yourself before adding it to the vegetables. It’s great for low-water content foods like asparagus or garlic, or for when you want to leave the vegetables whole. Instead of weighing the vegetables to get the salt content for the brine, you take between 2-5% of the total weight of your water. Place your veg inside a sterilised fermenting container and pour the water in until the contents are submerged – this is the exact amount you’ll need. Then, pour the water into a separate container and measure it to find out the amount of salt required. Create the salt solution then pour it back on top of the vegetables. Keep them submerged with a weight, seal, and store in a cool dry place, burping it twice daily for 14 days.
Experimentation
As the process is so ancient, you’re unlikely to be creating anything that others haven’t done before. For some, that might sound disheartening, but it does mean that there will almost certainly be a how-to (no matter how rough and ready) on whatever you so choose to ferment. Some examples out there that we love:
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Fermented white asparagus by Noma. The first recipe in their book, The Noma Guide to Fermentation – an absolute must for anyone interested in learning more – and it’s mind-bendingly good. Floral and complex yet punchy.
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Fermented fries by Appetite Life. We’ve tried them and can say they’re an outrageously good adaptation of a junk food staple.
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Fermented hot sauces. Blended wet ferments, with an abundance of wild and wonderful combinations to be discovered. See below for a recipe we love.
To conclude
It’s our belief that you should always have a jar (or two) of something fermented skulking around your fridge. A fermented ‘goes on everything’ hot sauce for example, or a kimchi for your poke bowls or to take a cheese toasty to lofty new heights – trust us on that, you’ll never look back.
Fermented hot sauce
- 12 yellow and orange habanero chili peppers
- ½ a pineapple
- 1 yellow bell pepper
- 8 fresh garlic cloves
- 1 inch of fresh ginger
- Salt
- White wine vinegar
Wearing gloves, stem and roughly chop the habaneros and bell pepper using a sharp knife. Peel the ginger and cut it into thin strips. Take the skin off the pineapple and cut it into chunks. Put everything in a sterilised jar and fill it with water. Pour the water into a measuring jug and make a brine by adding 2% of its weight in salt. Once combined and dissolved, pour the brine over the rest of the ingredients, making sure they’re fully submerged. Seal the container and store in a cool, dark place for at least 14 days, burping it twice daily.
After 14 days, blend the solids, adding the brine until it is a desired consistency. (Optional): add white wine vinegar and salt to the sauce at the end to reach your desired salinity and acidity.