Introduction: How to Make Your Own Fermentation Lock (Not a Balloon!)

Picture of How to Make Your Own Fermentation Lock (Not a Balloon!)

Are you thinking about making your own wine or beer? There are lots of quick and simple recipes out there for making wine but many of them suggest you use a balloon as your airlock. While this is very cheap and practical, I have found that many people claim it can leave a "rubbery" taste in your drink.

Commercial airlocks are not expensive by any means, but if you are like me and don't live close to a home brew store, you are on your own. Ebay sellers want ~$2 plus whatever gouged shipping charges they feel like putting on top of that. I have a simple solution for you, you can make your own super cheap one for less than $2 and maybe even free if you have all the stuff lying around!

I list 2 different methods, one is the bare minimum way (~36 cents plus some spare things you probably have lying around) and the other is the recommended way (a little under $2). I only have pictures for the recommended way but the diagram I use can be altered to work for either method.

Step 1: Materials

Picture of Materials

Bare Minimum way:
- Tape
- Pen
- Plastic tubing
- Jar (clear is best)
- Water
- Something to punch a hole with

Recommended way:
+ Hot glue gun
+ 1 Nylon barb and matching nut (I got this from the hardware store, ~$1.25)
+ Plastic tubing (~ 2 feet, depending on where you will be placing your jar)
+ Jar (clear is still best)
+ Water
+ Drill

Step 2: Methods

Picture of Methods

This is my illustration, hopefully it is pretty straight forward. I have some detailed instructions below...

1: Cut a hole in a box
Drill a hole in the lid of your fermentation vessel (or punch a hole in it, however you prefer to make holes). Make sure that it is very close in size to your nylon barb (or pen top). If you make the hole too big you risk not being able to make the seal airtight.

2: Put your junk in that box
Place your nylon barb into the hole you made in the fermentation vessel's lid (the barb should be on the external surface). I got a nylon barb from the hardware store for about $1.25. Lock it down by placing some hot glue around the hole and then quickly bolting the barb to your lid with its corresponding nut. If you are not satisfied with the seal, use more hot glue around the cracks where air may escape.
If you are doing the bare minimum method, put the tapered pen piece in the hole (tapered end facing outward) and tape it down like hell. I am assuming duct tape would be the tape of choice for this method.

3: Make her open the... I mean hook up your tubing
Hook up your plastic tubing. I bought mine from the hardware store for 18 cents a foot but I am sure there are plenty of places you can get it (Maybe some aquarium tubing from a pet store? Not pre-used though, that would be unsanitary). Either way, I bought 2 feet of tubing which worked out quite well, you may need more if you are not using a bucket as a fermentation vessel and have to set the jar somewhere farther away. As explained in the step's title, hook up the tubing to your barb (if using a pen tip you may want to using something, like tape, again to make sure your seal is still air tight, this problem is not as prominent in the barb method though).

4: Cut many holes in your jar's lid
Cut a main center hole in the jar's lid that is large enough for your plastic tubing to fit in, the size of this one is not that important. I place a little bit of tape around the rough edges of the hole as to not damage my plastic tubing. Also, poke many smaller holes around the center one to allow CO2 to escape from you airlock jar.

5: Place your tubing below the water level
This is pretty self explanatory, fill your jar about halfway with water and place the tube below the water level so that CO2 can escape from your vessel but will not come back in (due to the water barrier). I found that the closer the tube is to the water level (while still being below it) the quieter the bubbling noise is.

Step 3: Results

Picture of Results

There you have it! You now have your own homemade airlock and it cost you less than $2. Be proud of yourself.

Also, I recommend using water or vodka in your airlock, not sanitizer. This is what I found about it on (the greatest site ever!).

"Many brewers simply fill the liquid chamber with water, which in itself acts as a sufficient barrier to contamination. Others use a sanitizing solution in their airlocks. However, this is generally a bad idea with a small airlock. Sanitizer does not offer much, if any, additional protection, since airborne bacteria or wild yeasts are unlikely to be able to pass through any liquid and become airborne again in sufficient quantity to spoil beer. More importantly, under some circumstances, material from the airlock can be sucked into the fermenter, and even unboiled tap water is better for your wort or must than most sanitizers. As a compromise, some brewers use vodka, which is sanitary but will not contribute any flavor or character to the finished product other than a small amount of alcohol."

Step 4: Discussion

Picture of Discussion

Let me know if you have any improvements, comments, or airlock ideas of your own!
It would be cool if someone did this but had their excess CO2 go to a plant containment vessel to try to boost their plant's growth...just an idea!

Get your drink on.


DianeE14 (author)2017-05-01

I am looking forward to using this method, as I have made some wines using the balloon system. They came out well, but have been looking for a better way to do things. This will work out well, as I have all the "stuff" [jars, glue gun, new aquarium hose, duct tape, jars] So I am looking forward to seeing how this works as I attempt to make some dandelion wine this year.

mmmelroy (author)2016-06-24

for those that only buy a bucket and lid, but need a fermentor, this is the TRICK! save the few $ and make your own...

finfan7 (author)2009-04-07

This is interesting but my first question is immediately: did your setup not come with a free airlock?

ralegg (author)finfan72009-04-07

finfan7, My whole setup was made from scratch so unfortunately I didn't already have an airlock. The fermentation vessel shown is just a food-grade, 5 gallon bucket that I happened across, which I then made the enhancements as shown above to get my final setup.

DeeRilee (author)ralegg2013-10-23

One thing that should be noted regarding 'food-grade' buckets......don't reuse one that had previously possibly contained vinegar. You will likely end up with a batch of vinegar for your troubles. My father made his own wines & beer, and that was one thing he always cautioned's impossible to get every trace of vinegar out of any bottle, jar or bucket, and a trace CAN turn your wine into 'wine vinegar'.

Wonderful Instructable!!!!

finfan7 (author)ralegg2009-04-07

That's cool. I got mine as a gift. Brewers in my area are kind of lucky. We have a Brew-Your-Own Store right in town. The prices for hops are fairly reasonable. Do you do wine, beer, or both? I've been wanting to try my hand at wine.

ralegg (author)finfan72009-04-21

Currently I have only made wine but I am looking to try making beer next! I hope wine works out for you if you give it a try!

kotpet (author)2009-11-20

Very good instruction. I would add that one don't need a lid on the receiving can. Just my 5 cents. Good luck to all!

DeeRilee (author)kotpet2013-10-23

I believe the only purpose of the lid on the "receiving can" was to hold the tubing in place.

uberchoob (author)2012-10-08

Awesome Ible! I'm brewing up some ginger ale tonight when I realized I was out of balloons... Then I found this! Lifesaver :)

I'm brewing directly in 32oz bottles, so I took an old wine cork and drilled a 3/8 inch hole in the center and shoved some 3/8 inch tubing in it. Then drilled out the same in the lid of a perrier bottle I had, punched a couple holes in it, filled it with water and called it dandy.

Thanks again!

RainDog07 (author)2012-06-04

I just run the blow-off tube into a container of sanitizer located below the fermenter.

Homepwner (author)2012-05-11

The sports drink "Powerade" has a sippy lid on it that has a silicone seal with an X cut into it. I think it"s called the "powervalve" I don't brew but watched my Dad do it for years... long ago. I want to see someone fit this as a dry airlock to their carboy! I think it would make "fartlike" noises when it vented HAHAHAHAHAHA! please post a video if you try it.:) sorry, I'm still a Kid at heart!

codyg102 (author)2012-01-11

Another option for quieting the bubbling might be an aquarium air-stone (from you friendly neighbourhood pet store) in the water jar (much smaller bubbles = quieter?). Haven't actually tried it; just a thought.

cider101 (author)2011-12-17

I'm making apple cider for the first time soon and am trying to learn all i can. once all the ingredients are in the fermenting bucket is there suppose to be no oxygen/air at all? meaning the bucket becomes a vaccuum chamber?

kiss my donkey (author)cider1012012-01-10

Yes. No oxygen because this can cause it to get contaminated and then rot.

Green Goddess (author)2011-12-14

This is so brilliant!!! I am officially inspired! I signed up just because of this! Thanks for the help :)

2muchfreetime8 (author)2011-05-16

i love the d**k in a box reference. and interesting instructable, gotta say

adanielsriveros (author)2011-03-08

I just used this for my ginger beer, it worked perfectly! Since I don't have wheels right now, it is my best option, and much better than continually opening the brewing vessel. Thanks!

brb112988 (author)2009-10-14

hey guys i just wanted to throw my 2 cents in cuz im very interested inthis and want to learn to make my own wine and beer and stuff but for aone way valve is there any way that a gasoline sifoner could be used imean if u have one end in the fermenting barrel and the other end justhangind down couldent you just let it ferment and then pump it a fewtimes a day to let the air and toxins out of the fermenting barrel?

 The only thing you are letting out of the fermentation barrel is CO2, the reason you add air locks is to stop stuff getting in like insects, bacteria, bodily fluids.

So no you should really have an airlock that allows carbon dioxide out but prevents stuff getting in.

Some what correct...However, the airlocks main reason is to keep oxygen OUT.

As brb112988 said, you must vent the bag/barrel a few times a day (like making prison brew) or things can explode. Draw back to this is that air and wild yeasts are let in each time the bag is opened. Which can ruin the taste and alcohol content.

An airlock type device is needed to keep the oxygen out and allow the co2 to escape. yeast without air produces alcohol, with air you'll just make vinegar.

genera (author)2011-01-07

i have a question how would the air lock ever be able to drain back when the system is pressurized? at no time could that happen

anahatabalance (author)genera2011-02-05

right, your brewing preesure should always be positive unless there is/was an airleak.

anahatabalance (author)2011-02-05

This may be needed for large brewing ops, however, most people are doing 5 gals, so a store bought airlosk is only like $2-3 and don't have any leaks or fuss. I think this is something that is just easier to buy and do it right.

timntek (author)2010-11-03

Try doing hydroponnics from the jar... Just a possible idea for cuttings

kieronrob (author)2010-10-15

I have tried with aquarium non-return valves and found that they require to much pressure, with the result that the bucket lid popped off! I used a similar setup but with just a glass filled with a mild chlorine sterilizing solution which worked a treat. The jar just makes more sense as you won't have the pipe popping out if it gets bumped. The sterilizing solution also seems to kill any odours that might be in the CO2 and prevented the women from complaining of the beer smell in the kitchen! This will be tried this weekend when my next batch goes in.

jpark1 (author)2010-09-12

You shouldn't use anything on the end that increases resistance to the flow into the blow-off container, and your blow-off container volume should be less than the volume of your tube if possible. most hb'ers use a 1" id hose that fits snugly into a carboy neck

Darkwerk (author)2010-02-08

I like the insctructable. It's a great way to get it done when fermenting. The only thing I noticed was you used water. I brewed beer for two years and I found that using a cheap vodka (80 proof) works much better. It doesn't allow stuff to grow in it like the water and if you accidentally get some in the beer it won't harm it like that water will. Especially when it fist starts fermenting it can get a little crazy.

static (author)2010-01-31

 When dad made his home brew, all he used was a 35 G. crock with a heavy towel covering the top. No fermentation lock that I can recall. Can't recall anyone complaining about the lack of alcohol content either.

graeme.t.cooper (author)2009-09-13

Re plant containment. I was thinking aquarium

Grady (author)2009-09-09

Couldn't one use a rubber gommett in the hole before inserting the tubing for an air-tight seal?

Lupigarth (author)2009-08-17

I've used something similar with making mead where a blow-off tube is used that just fits within the 5-gal carboy neck. I'm not sure of the diameter (it seems like it was about 1-1/4 - 1-1/2" ID) but that was good as it allowed junk to go into (and past) the airlock without getting clogged. I did experience a vacuum that nearly sucked water back into the carboy. Raising the carboy above the airlock did help with the vacuum, but it was strong enough to still pull a couple of feet of water.

gregd888 (author)2009-08-10

Lmao I made a homemade hookah that looks something like this

lol i know what y mean.

unaffiliatedperson (author)2009-05-23

good job. way easier to understand and construct, use than the little ones that look like a mini film canister. and can handle large volumes

I just have to say GO SLEEPY SLEEPY RULES SO DOES BOB BARKER and i guess i'll say AOL

cowboy709 (author)2009-05-18

I have seen a method similar to this but using several fermenting buckets and all the tubes going to one jar of water. very efficient

hg341 (author)2009-04-04

or! you could pump the co2 back in the wine beer and have a soda for adultz it was well done and i now know how to make a airlock

finfan7 (author)hg3412009-04-07

Beer contains CO2 from a later step anyway. (that's what gives it its head) And bubbly wine is what is commonly called champagne. (though most of what is called champagne is just sparkling wine)

hg341 (author)finfan72009-04-07

oh... i didnt know that

lemonie (author)2009-04-05

So this can suck-back into your fermenter, and there's nothing to keep the water sterile? While gas is coming out the lock is really only useful to exclude insects, but when the fermentation stops, it's a bit different.


ralegg (author)lemonie2009-04-07

Good point, the suck back could be avoided by placing the airlock jar below the water level of the fermentation vessel (ie. on the floor, but would require longer hosing). However if something goes horribly wrong and your airlock vessel starts to suck back liquid from your fermenter, you could either: Overflow your brew all over the place or
Possibly suck back nutrients into your airlock, which would then definitely become a habitat for bacterial growth.

Also, I did post that a compromise between the water/sanitizer debate is that some people use vodka (because if you buy the good stuff it should be odorless and tasteless) which will not greatly affect the outcome of your brew except make it a little higher in alcohol content.

Thanks for commenting, and thanks to all for the feedback, this was my first Instructable

lemonie (author)ralegg2009-04-07

One easy design modification would be to fit a 'can' to the end of the tube, so that suck back lowers the level of liquid in the jar so much that it will suck air under the rim (instead of liquid up the tube). I've made a horrible job of editing your image, but hope you can see what I mean. L

Building Books (author)2009-04-05

when I was reading this I was listening to my air bubbler in my aquarium making it's usual racket and had a few ideas. With the air pump it has a bit in it that stops the reversal of air, could use that somewhere in the system (don't know where? maybe if you want to trap the resulting CO2) and could you use an air stone on the end of the tubing to make the bubbling quiter? Doesn't make things cheaper, unless you can get an air pump tubing kit on the cheap.

ralegg (author)Building Books2009-04-07

Good idea, I may need to look into buying some sort of a physical "one way valve" but I become concerned with the idea because if it failed I would hate to see the explosion :( Although, if it had an emergency blow off valve that released pressure if needed, that could be a possibility. Also, I have an air stone I haven't used yet for my own fish tank, I will have to check it out. Thanks for the ideas, I will look into it and if I figure something out I will post it as a bit of an 'extra' since as you noted yourself, I was going for minimum $$ spent

Holden_vy_s (author)2009-04-05

Gimma sum of dat purple drank. Good instructible, very easy and all materials are easily available. 4 stars Now make an ible on constructing a still so beginners (like me) could put it to good use!

About This Instructable




Bio: I enjoy growing citrus plants, building things that capture green energy, constructing car audio systems, and nearly any DIY project.
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