Fermented Onion Recipe
Fermented Onions are instant burger boosters and improve any salads or sandwiches. Do you have some extra onions that you'd like to preserve? Maybe they aren't the storage kind that keep in a basket for months. Here is your solution: Ferment your onions! They will store in the fridge for a year or more and will produce probiotic live bacteria to improve your gut health. They are also a great medicinal food to have on hand for cold and flu season.
Equipment
- Quart size mason jar - a standard canning jar works great or my favorite, a Bormioli Rocco Fido jar
- A weight - I recommend a glass fermentation weight
- A fermentation lid - if you use a mason jar, seal it with a fermentation top or airlock if you can, otherwise use a standard canning jar lid.
- Knife and Cutting board
- Tamper - I highly recommend a pickle packer type wood tamper
Ingredients
- 2-3 medium white, yellow, or red onions, sweet or regular.
- 1 tablespoon salt
- 1 pint of filtered water
Optional ingredients
- 1/4 cup starter culture - the juice from a previously fermented vegetable
- 1/2 lime - use with skin on if you're making a remedy, but it will make the onions bitter. Use just lime juice to avoid bitterness.
- 1 tbsp caraway seed
- 1 tsp black peppercorn
- 1 tsp turmeric, dried or a few fresh slices
- 1-2 tbsp pickling spices, use your favorite
- 1-2 hot chili peppers
- ginger, a few thin fresh slices or dried
Instructions
- Cut the onions in half and slice to your desired thickness. Reserve a large piece of the outer skin.
- Place the spices you like into the jar.
- Add the onion slices, layered with lime slices if you use them (see note*). Keep adding onions and pack them into the jar tightly to within one and a half inches from the rim. Use a pickle packer tamper if you have one or your fist.Cover with the reserved large piece of onion skin to keep floaters down.
- Make your brine. Mix 1 pint of water with 1 tablespoon of salt. If you're using the optional previously fermented vegetable brine as a starter culture, add about a quarter cup of it now. You can cut your salt use in half if you prefer, when using the starter culture.Pour the salt brine over the onions and be sure to cover them with brine. Make more brine if necessary.
- Place a weight on the onions. They should be submerged in the brine and the brine should cover all of your onions so none of them are exposed to the oxygen.
- Seal your jar with a fermentation lid or just close your hinged top with seal in place. (Note: If you use a regular mason jar lid, you will need to burp it once a day to release the pressure during fermentation).
- Place your container in a darkish corner. Put a bowl under it to catch any overflow that might ooze out. This will be its home for the next 1 to 3 weeks . Try to find a place where the temperature stays above 70 and below 80℉. This will be your best fermentation temperature, especially for the first few days. But fluctuations are ok and a little higher or lower is fine, and no big deal for short periods.
- Check it occasionally. You might need to burp it once a day if you're using a sealing lid. Just quickly loosen the lid enough to let the pressure escape, and tighten it right up again. Don't remove the lid unless you have an issue to deal with. We don't want to introduce oxygen into the jar. You don't usually have to do anything if you use a fermentation lid, just check to make sure it's fermenting. You'll see the brine get cloudy, bubbles start forming, and the liquid expanding, possibly oozing out of the jar.
- Let it ferment at least 5-7 days, but ideally 3 weeks. If you're impatient, you can give it a taste after a week. When you open the lid, smell it. You should smell that distinct fermentation smell. It should smell pleasant and tangy. Check the onions, are they firm? Does everything look good? Taste a piece of onion. It should have a salty and tangy flavor. If you love it at this point, you can place it into cold storage. The onions are not really done fermenting for another 2-3 weeks, but some people like the half fermented stage best. If you prefer the long-fermented method, keep it out at room temperature for another 2 weeks and give it another taste.
- You can now place it into cold storage for long-term keeping. Cold storage will slow the fermentation down and make your onions keep for a very long time. At least a year. If you have a cool corner in your home, that is under 70 degrees, you can also keep it at room temperature for quite a while longer. But it won't keep as long as in cold storage. However, it will stay delicious for several months at least. Let the smell and taste be your guide as to whether it's still good. Most likely you'll have eaten it well before it declines. If it smells bad or you find that it is turning mushy and unappetizing, it's probably time to feed it to the compost, where it will be useful as an effective composting accelerator.
Notes
*Unpeeled lime slices will give your onions a bitter flavor. They are really good for a cold remedy, but if you want to avoid bitterness, use just the juice of the lime or omit altogether if you don't have any.