Should you make water kefir with an airlock or just cover it with a cloth? Is the process more like kombucha or sauerkraut?
I have been making water kefir for several years now and so far have not used an airlock. I cap the jar tightly during the second ferment to increase carbonation. (An airlock during the second fermentation is a good idea, as I have experienced an explosion due to the build up of gasses.)
Recently my sons and I performed an experiment to test the hypothesis that oxygen is beneficial during the first fermentation period, and therefore a cloth cover is preferable to an airlock. The cloth cover allows oxygen to nourish the growing culture. The airlock keeps oxygen away, but allows carbon dioxide to escape. This is vital for vegetable ferments such as sauerkraut or kimchi, but not healthy for ferments that need oxygen such as kombucha or wine.
What are water kefir grains? They are similar in nature to a kombucha SCOBY (Symbiotic Colony of Bacteria and Yeast.)
The scientific name given to water kefir grains is tibicos, which according to wikipedia, “are a culture of bacteria and yeasts held together in a polysaccharide biofilm matrix created by the bacteria.”
Fundamentally, yeasts require oxygen in order to grow. If your grains multiply during the initial fermentation, it is a sign the culture is successful.
We started with two half gallon jars, filling each with the same amount of grains (3 ounces), sugar, and water. We added the same amount of molasses to each. (Molasses offers a nice boost for the grains since they thrive on minerals as well as sugar.) We covered the first with a cloth, the second with an airlock.
After 48 hours, we strained both and weighed the grains.
Colin performed his own experiment with similar results. Read his account here.
While our experiment tells me that either method is acceptable, I think I’ll keep letting my kefir breathe during the first ferment.
Would you like to perform your own experiment, or make your own water kefir? View the recipe here.
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kathie says
Thank you so much for this water kefir experiment. I have 2 air-lock lids, but didn’t know if I could use them on my kefir (rather than vegetables). This gave me all the information I need to know that both methods will work, but a cloth works better (especially if I want my grains to grow).
Andrea Fabry says
I’m so glad it helped, Kathie! Thanks for the feedback.
Brittni says
Hi i have a question. My grains look like they are broke down. Very small. What am I doing from. This is the first time in the water after dehydration
Andrea Fabry says
I would keep trying to grow them. It may take awhile for them to come back to life.
marco polo says
Cool experiment! I’ve been getting into fermentation lately and was wondering about this exact topic. This was a great, concise explanation, thanks!
Andrea Fabry says
Oh I’m so glad to hear! Thank you for commenting.
Gerhard says
Hi
Please help. I have recently acquired these great plants and know little about them. Your experience above seems as if you can possibly help.
I make water kefir with Rooibos tea(South African) and Treacle. Previously I did not close the container but on the last occasion I accidentally closed it tight. Now it looks like there is some other fungus(whitish) floating on the mixture and it smells more alcoholic like than before.
Is it possible that these poor guys may have died?
Andrea Fabry says
The white fungus could be Kahm yeast which is actually harmless. The fact that is smells alcoholic tells me that your grains became yeast heavy. I don’t think they are dead. In order to balance them again I might rinse them in filtered water and let them be in the fridge in some sugar water for a week or two. It’s a good way to allow them to re-balance. I honestly don’t think all is lost. The loss of balance could have occurred when you closed it tightly. If you use all treacle and no regular sugar then it become yeast heavy from what I understand. I would use 1/3 part treacle to 2/3 parts regular sugar. I hope this helps. Please do keep me posted!
SG says
Hi there,
I’ve recently noticed that my fresh water kefir (no additives: made with tap water and white sugar) had started to initially develop pink stains and recently some of the grains had black stains on them almost like a mold…I was wondering if you knew what this meant and if the grains were still safe to use?
Thanks,
SG
Andrea Fabry says
You can try to rehabilitate them by rinsing them with filtered water and leaving them in the fridge in some sugar water. Sometimes this “cleans” them. The discoloration is not a sign of healthy grains. I might discard them and start fresh.
Tom says
Grains prefer oxygen, that’s correct. But most bacterias will not strive in the oxygen environment.
Pam says
I was wondering about this, as I have read somewhere that if it is not airtight bad bacteria will get in and destroy all the good. Any ideas on this?
Andrea Fabry says
That’s true with sauerkraut, but when there is a combination of bacteria and yeast (such as kombucha) then oxygen is good. They balance themselves out. Sauerkraut is strictly bacterial as I understand it.
Stephen Reed says
Thanks for the advice Andrea. I’ve been making milk kefir and other exciting ferments for ages, just started on water kefir and this is what I needed to know. Perfect timing.
Leonard says
Oxygen changes the taste of the outcome. In the case of kefir it means too much (lactic) acids. Oxygen is the fast and cheap way to make vinegar.
Jacky says
Hi I’ve started fermenting my water kefir with closed fido jars Although not completely airtight I find that the smell of the water kefir after first ferment is less yeasty smelling than with just a cloth cover. So I prefer this method now.
Virginia Linnell says
Great post. Was just wondering which way to ferment the water kefir whether to seal or to allow oxygen. There many differences in opinion. For now, based on your findings, will continue first ferment aerobically. Thanks.
Andrea Fabry says
Thanks for taking the time to share, Virginia.
Guillaume says
Hi What is the longest one can store a bottle of Kefir after the second fermentation ? I do a 2 nd fermentation for 2 days with loads of healthy spice ext .. i only do one burp after the 1st day and then thraight to the fridge after the 2nd with loads of fizz.i suppose the fermentation does cary on although refrigerated ? Meaning it wil explode if left for to long ?
Andrea Fabry says
It shouldn’t explode in the fridge, but it will slowly increase in fermentation. I’m not sure it will go “bad”, but might not taste as good.
can demir says
When i use aerobic it turns vinergar easly. Is there a way making it non vinegary but still aerobic?
Andrea Fabry says
It always leads to vinegar the longer it ferments. The only suggestion I have is to stop the process sooner so it doesn’t become that acidic.
Lisa says
Great experiment, but testing the kefir water also is important,cause knowing if the kefir water which is what we consume has more or less bacteria , taste , flavour , colour, etc, after aerobic and anaerobic fermenting is an imortant part of you observation checklist.
Cubo says
Lisa, how could one test to see if the water kefir has more or less bacteria? I am new to this but loving some of my second ferments over others.
Wynonah says
What do I do if my water kefir gets kahm yeast?!
Thx!
Andrea Fabry says
Kahm yeast is perfectly safe. You can strain it out if you would like.
Hendri says
How much sugar and water u use for half gallon jar.
Can I growth the kefir grain without use mollases?
Andrea Fabry says
http://it-takes-time.com/2014/03/10/how-to-make-water-kefir/ This post has the recipe. You don’t have to have molasses.
Pati says
Hello, I left my water kefir grains in an airlock jar with very little sugary water for a couple of days as I did not have sugar at home to start a new fermentation.
when I put the grains again in sugary water, they didn’t seem to do anything. The water tastes of sugary water and no fermentation seems to have taken place. Is it possible that I have killed my kefir grains because of lack of oxygen?
Andrea Fabry says
Maybe some time and repeated attempts will bring them back to life! I’m not sure on this.
Shawn says
Any data on whether the grains produce more alcohol in an aerobic or anaerobic environment?
Andrea Fabry says
Hmmm…excellent question! If I get an answer I will let you know.
Eva says
I found this research paper, “Oxygen and diverse nutrients influence the water kefir fermentation process”, that I want to share with you. You will get different kinds of culture depending on the amount of oxygen. With oxygen you will get more acidic acid (vinegar) in your water kefir, like some of you have already noticed.
https://www.sciencedirect.com/science/article/pii/S0740002017311498