Tell Me More About This Airlock Thing You Mentioned

bubbling airlockHi:
I have always made my wine in a humongous stone crock.  What is an airlock thing that is mentioned?   My wine is really good, and I’ve never gotten sick from it.  Nobody else has either.  So would that airlock thing make my wine better???  By the way, I make Elderberry and Choke Cherry wine.
Thanks, Lois
Hello Lois,
I’m glad you brought this up. Many people misunderstand the role airlocks play in home winemaking. Now is just as good as time as any to clear things up.
An airlock is basically a water trap that you attach to the neck of a jug with the aid of a rubber stopper.  It cannot be attached to an open vessel such as the stone crock you are using. It needs a neck of some kind. You put the rubber stopper in the opening and then insert the airlock into a hole that is in the rubber stopper.
You fill the airlock halfway with water. As the gas comes off the fermentation, it bubbles through the water within the airlock and then out of the container. At the same time this water keeps outside contaminants and bugs from getting into the wine. This helps keep the wine free from spoilage.
The first thing I would like to point out about an airlock is that it has nothing to do with the quality of the wine you make. It will not make a good wine great or an average wine good. It does nothing of the kind.
What an airlock does is reduce your chances of having a wine spoil. It keeps your wine protected from infection during and after the fermentation. It does so by creating this barrier between the fermentation and airborne molds and bacteria. Allowing these little nasties to get into your wine and then giving them a chance to grow is the essence of spoilage.
If the wine is fermenting and foaming like it normally should, all these foreign intruders do not really have a chance to take over a wine. There is CO2 gas coming off the fermentation, keeping fallout from landing directly into your wine must.
So just getting to the wine is a big challenge for these little spoilers. But beyond this, if they are able to get into the wine, having an opportunity to grow is very slim for them. All the yeast activity from the fermentation keeps them in their place and even destroys them in most cases.
What all this means for you, Lois, is that using your stone crock for fermenting your wine is fine up to this point. The wine is fermenting strong and spoilage is close to impossible during this time.
It is when the fermentation begins to slow down that you could have some issues with spoilage. Fermentations do not typically stop all at once. They usually taper off over the course of a few days. As the fermentation becomes less and less active, the window of opportunity becomes larger and larger for contaminants to get to the wine and spoil it. It is in this context that the airlock becomes valuable and in my view a necessity.
Happy Wine Making
Customer Service
Ed Kraus is a 3rd generation home brewer/winemaker and has been an owner of E. C. Kraus since 1999. He has been helping individuals make better wine and beer for over 25 years.

8 thoughts on “Tell Me More About This Airlock Thing You Mentioned

  1. The airlock is on and filled half way with water, how do I know that it is working….fermenting?

  2. Hello Robyn, It will be easy to tell. You will actually see bubbles go through the water.

  3. I just read your article on the use of an airlock. You make alot of great points that I really didn’t think about. I use an airlock after fermentation but have never used one during the fermentation process. I alway thought that the yeast needed oxygen to do it’s thing. With the CO2 produced as a byproduct from the fermentation how much oxygen is required? Mose fermentation containers only have a small area for oxygen/CO2 once there a closed with an airlock in place. Without ample oxygen for the yeast will the fermentation process take longer or not complete causing problems later?
    Thanks I enjoy your news letters.

  4. A fermentation that is done in a fermenter with a stone crock profile, like a bucket, will start quicker and ferment harder than a fermentation in a fermenter with water bottle profile or small neck. This is assuming that an airlock was not used in either case — all things being the same. The reason being air has a harder time getting to the yeast in the case of the later.

  5. I have used an airlock during all my fermentation and have had great luck. As far as oxygen there are aeration stone and oxygen cylinders you can use to infuse a greater oxygen concentration in your juice or wort, I have never used one and seem to have thorough fermentation. I have also used a good quality vodka in my airlock as an added "sanitizer" for any air or liquid that may be drawn back in due to pressure changes after fermentation. I don’t have a place with a stable temperature to ferment my product so once the primary fermentation is complete, temperature changes can cause a low pressure condition in the container and draw air and liquid into the wine. When you wake up in the morning and find you air lock half or completely empty, you have a panic attack from wondering what was in the water that is now in your wine. I started to use a good quality vodka right afterwards.

  6. I have been making wine for four years now. Most of my wine is too sweet. What is a good recipe to make dry wine?

  7. Irene, you should check out our recipe page on our website. It’s under "Resources & Guides". All these recipes come out dry. If you do want them sweet, just add sugar and potassium sorbate before bottling.

  8. I made wine years ago and always used an air lock. Tried to run just sugar and water with some yeast (Red Star Active Dry) and nutrient. Never saw a bubble. Any idea where I went wrong?


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