Should You Put a Lid on Your Ferments or Use a Cloth
Getting confused about whether to seal up your ferments or not? Look no further, we have compiled a quick set of guidelines for kefir, kombucha and fermented vegetables.
If you have looked at a few different sets of fermentation instructions, then you might have noticed that sometimes one is instructed to use an airtight lid, warned against the dangers of any air getting in, and other times are told to merely cover you ferment with a cloth!
This can get confusing, so we are going to have a look at the holy trinity of ferments, kefir, kombucha and fermented vegetables, and see what’s what with the issue of whether to cover or not.
Fermented vegetables are probably the ferments with the most confliction with regards to covering. Some fermenters swear by airlocks, and others leave theirs wide open with merely a dish towel to keep out dust and bugs. So we have to ask the question:
Should I seal up my fermenting vegetables? Yes.
The answer is yes, and here is why. The less fresh oxygen you let into your fermenting vegetables, the less chance there is of mold growing on the surface.
What about all the people who do not use lids?
This does not mean that you cannot ferment veggies open topped with a cloth cover, as many people do and have success. However, you will probably have to scrape off mold from the tops – and ingesting mold is not recommended.
What can happen if I do not use a lid?
Personally, I have also noticed that if a vegetable ferment is exposed to excess air, even if you do not encounter any mold, there is a high chance of kahm yeast developing, and the fermentation can often take on a less than pleasant smell.
What is the best way to seal my ferment then?
The tiptop best way to seal up a vegetable ferment is by using an airlock. Airlocks work wonderfully, allowing excess pressure to escape, while not letting any new air in. If you are using an airlock on your fermented vegetables, then you also do not need to worry about cracking the lids of your veggies to release pressure and reduce explosion risks.
But do not think that you HAVE to use an airlock. You can successfully ferment in bail wire jars, mason jars, and ordinary jelly jars. However you will have to burp them daily, and you might find that sometimes they have a less crisp and clean smell to them than ferments done with airlocks.
When it comes to sealing, kefir is quite an interesting one. Instructions for kefir making almost unanimously (but not quite) instruct one to leave kefir open, or covered with a cloth. However there are a few renegades out there who have been protesting that kefir is actually better fermented with a lid screwed on tight! Although it seems most sensible go with the majority vote, it is hard to ignore the advice of something like Donna Schwenk from culturedfoods.com who has been making kefir for years – and as she states ‘always shoots straight with you’.
Is my kefir supposed to be open or closed? – It is up to you
While in our guides to kefir making we have gone with the conventional method of using a tightly woven cloth covering for kefir, and you can make good kefir this way, the fact that there are people who seal their kefir and feel that it gives a better product means that this is an option.
Why would I use a lid for my Kefir if it can be made without one?
The reason why putting a lid on fermented kefir can result in better kefir, is that ferments can sometimes cross pollinate! Other fermentation such as kombucha, can cause cross pollination of yeasts and bacteria in your kefir. While this will not harm you, sometimes cross pollination can result in discoloration on the surface of your kefir, or strong yeasty tastes and bad smells.
So should I use one or not?
If you are making kefir as well as other fermentations such as kombucha, then you can try out putting a lid on your ferment to avoid the hassles of cross pollination. If you do not like the results of this, you can always switch back to lidless fermenting, but make well and sure that there is a good few meters between the kefir and other ferments.
If you do not have any other fermentations going on, then it is not likely that you will get cross pollination, and you can confidently continue to open ferment.
Kombucha is one of the ferments where thankfully there is not too much confusion. While one can seal up jars of dormant SCOBYs which you are storing, sealing a container of kombucha which is busy fermenting is not a good idea. This is because the kombucha SCOBY needs air to do its good work, and without it fermentation will take a knock.
Must I always let my kombucha ferment open? Yes!
By open of course we mean with a cloth covering securely fastened to keep out vinegar flies – but other than that do not seal up kombucha, and in fact try and make sure that it has a ventilated place in which to sit and ferment. Closed and stagnant cupboards are not ideal. In addition, kombucha kept in a cupboard or stuffy room will start to make the space smell pungently like vinegar!
And there you have it! The low down on whether or not to seal up a ferment. Interestingly, each one of our three sits on a different piece of the scale. Vegetables ferments one can definitely seal up good and tight, kefir you can go either way depending on what other fermenting you got going on in your kitchen, and air hungry kombucha really needs to be open to produce fizzy, tasty booch!