Fermented onions are pickled onions funky cousin. They are much easier to make than the traditional pickled onion and taste amazing. And as an added bonus, like all fermented vegetables, they are incredibly good for you! I use these beautiful, tangy onions on loads of dishes, from dals to tacos. How will you use yours? Liz x
- onions (a mix of red and white or just one or the other)
- natural salt
- optional herbs/spices (eg bay leaf, peppercorns, coriander and mustard seeds, juniper berries, thyme, rosemary, chilli… anything you like)
- a cabbage leaf (or something similar)
Gather your ingredients and a clean jar, knife, measuring jug, measuring spoons and chopping board. There is no need to sterilise, but do make sure everything you are working with is nice and clean and well rinsed.
Make a basic brine in your measuring jug and put it aside to fully dissolve while you prepare the jar of vegetables. ***The basic brine recipe is 1.5 tbsp salt dissolved in 1 litre of water.*** If you are making just a small jar then halve or quarter the recipe.
Add a pinch of whatever pickling spices or herbs you’d like to flavour your pickled onions with to the jar.
Then peel and slice your onions and add them to the jar. Red onions, or a mix of red and white, will give you beautiful, bright pink fermented onions. Plain white are delicious too of course. Leave about an inch of head room in the jar.
Then pour the brine into the jar ensuring you cover the onions when they are pressed down, but still leave a little head space in the jar.
Pin the chopped onions down under the brine with the cabbage leaf. You may need to break it to size. Try and tuck it neatly under the shoulders of the jar so that everything is safely tucked under brine. Any floating bits of onion will be exposed to air and are at risk of going mouldy so tuck them under the cabbage leaf ‘follower’.
Add a weight on top of the cabbage leaf if it looks like it will float up over the brine. This needs to be something that is not corrosive when in contact with salt and water. Glass is ideal in this situation so a smaller jar or a glass ramekin is perfect. Otherwise you can buy specialist glass weights for this purpose.
Place the lid loosely on the jar to allow gases to escape during fermentation. If your lid does not fit over the weight, then cover the jar with a tea towel and secure it with string/elastic.
Put the jar in a bowl or on a tray on a shelf for one week to ferment at room temperature. It’s best not in direct sunlight as that would cause too many fluctuations in temperature.
Taste the onions after 1 week. They should taste vinegary and delicious, a lot like pickled onions. If you are happy with the flavour, remove the weight and follower and keep the jar in the fridge. Otherwise let it carry on fermenting at room temperature until you are happy with the flavour.
The onions should last for a long time in the fridge, at least a month but usually much much longer. Just keep an eye on them and no double dipping! Enjoy!