In this article you will find the answer to your question, what can I use if I don’t have an airlock?
An airlock is a really useful tool for homebrewers. However, they aren’t the most durable, and often we end up tossing them after a few uses. If you’re like us, you may have had that moment when you’re halfway through your brew and realize that you don’t have a spare airlock.
This can seem like a huge problem when you’re homebrewing, but in reality, there are some handy alternatives that you can use, or create if you’re stuck in that moment when you’ve started your brew, and don’t have an airlock available.
To be fair, we haven’t tried all of the options that we’ll put in our list, but we were given these ideas by other brewers who have used them and found them to be relatively successful alternatives. The options we’ll discuss in this article are the blow-off tube, the loose lid/seal & burp method, homemade airlocks, balloons or rubber gloves, and foil or plastic wrap.
Most of the options we’ll throw out aren’t great for regular use, but in a pinch, they are a great way to create an airlock situation when you don’t have an airlock.
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If we were going to pick a preferred option for an airlock alternative, this would be our pick. In essence, the blow-off tube is really an airlock of sorts, but without the airlock. Blow-off tubes create a way for carbon dioxide (CO2) to escape from your fermenter without the risk of plugging up an airlock.
Many brewers like to use blow-off tubes instead of airlocks when they have used a high activity yeast that creates a lot of krausen. Krausen is the foam that is formed during primary fermentation. Some yeast strains create a lot of krausen, and if pushed into an airlock, the foam can plug up the airlock and cause a buildup of pressure in the fermenter.
A blow-off tube utilizes the same hole in your fermenter cork or bucket lid that your airlock would. Instead of inserting the airlock, you insert a length of sterile tubing in the cork or fermenter lid and run it to a bowl, cup, or pitcher filled with water mixed with a sterilizer. This set-up creates an airlock of a larger scale than those that sit on top of your fermenter.
It’s hard to completely plug up the tubing with krausen. There is always a good stream of CO2 passing from the fermenter, into the tubing, and out through your sterile water.
Loose Lid or Seal and Burp
If we were going to pick a second-best alternative to the airlock, the loose lid or seal and burp method would be it. This is a pretty low-tech way to release pressure in your fermenter. There are two techniques here to try.
The loose lid method is best utilized if you are using a bucket fermenter. The idea here is that you place the lid of your fermenter on top of the bucket, and don’t press it down for a tight seal. Lots of homebrewers swear by this method, because if you leave it alone, you’re still keeping unwanted yeast, bacteria, and fungi into your beer, but at the same time providing a space for CO2 to escape.
Here’s the thing with the loose lid method – you can’t mess with the lid or you risk contaminating your beer. If you go with the loose lid method, you’ll need to leave the fermenter alone until you’re nearing the end of your primary fermentation. Also, this is not a great method if you’re using a high activity yeast. A big swell of krausen could push the lid right off the fermenter.
Seal and burp are along the same lines. In this technique, you completely seal down the fermenter lid, and then periodically “burp” or release a small section of the seal to allow any built-up CO2 to escape. We’re not huge fans of this method, because if you’re not burping your fermenter enough you risk building up too much gas that can either blow off the lid of your fermenter or just explode the whole thing.
The seal and burp method also seems to have a higher risk of introducing unwanted contaminants into your beer.
We haven’t tried this option ourselves, but if you want to give it a shot, there are plenty of resources on the internet to help you make your own airlock.
If you want an option that is more along the lines of a typical airlock, you can make your own. Homemade airlocks are almost always 3-part airlocks and are made from a variety of items that you can find around the house.
Like many other DIY projects, these can be awesome, or they can be terrible, depending on your DIY skills and the items that you use for your airlock parts. In our opinion, the best “homemade” airlock is the blow-off tube. It’s simple, doesn’t take a ton of time to put together and it always works.
This option brings back memories of elementary science fairs where half the kids had beer bottles filled with yeast and water topped with balloons in various stages of inflation. It’s the same principle with your fermenter.
First, this idea only works with carboy fermenters. Stretch a balloon or rubber glove over the top of your carboy and allow it to collect the CO2 released from your fermenting wort.
We’ve yet to find a balloon or rubber glove large enough for our bucket fermenter. We also recommend using this option only for low activity yeasts, or beer you’re keeping a close eye on. Eventually, the balloon will need to be “burped” or replaced. And you’ll want to do this before it pops.
Aluminum Foil or Plastic Wrap
This is another low-tech option that lots of homebrewers swear by. Many homebrewers skip the airlock all together and just cover the opening of their fermenter with a layer of aluminum foil or plastic wrap. We mostly see this with homebrewers using carboy fermenters, because the foil or plastic wrap can be attached to the neck of the carboy with a rubber band.
The theory here is that the foil or plastic wrap keeps the environment sterile, but CO2 can still escape through wrinkles or pleats in the material because it’s not a tight seal. While we’ve not used this method, it seems like a good alternative, and it feels a lot like the loose lid or seal and burp method that you would use on a bucket fermenter.
You don’t have to panic if you start your brew day and realize that you don’t have an airlock. There are plenty of alternatives that you can use in a pinch, or you may want to try as an all the time alternative to using an airlock for your home brewing processes.