How to Clean & Sanitize an Airlock: Step-by-Step Guide!

The airlock is one of the most important components in our homebrewing kit since it allows for oxygen and Co2 to be pushed out of the fermenter while not letting any external particles into it, allowing for the ideal conditions for fermentation to take place.

Having said that, since it’s so important that no external particles and oxygen make their way into the fermenter, otherwise, it could get infected, oxidized, etc., it’s of extreme importance that the airlock work as intended and that it’s clean and sanitized.

In this article, I will be explaining how to clean the airlock and blowoff tube step by step, what cleaning & sanitizing agents you should use, and more.

So, without any further ado, let’s get started!

To clean an Airlock you need to dissolve a strong cleaning agent such as PWB or fragrance-free dishwasher soap in a large bowl filled with water and soak the airlock in it for at least 30 minutes or until all the organic soils have been removed, then you simply need to rinse it in warm water to remove any particles left in the airlock.

How to clean an Airlock and a Blowoff Tube

Let’s first start with the steps you need to follow in order to properly clean the airlock since cleaning the blowoff tube is almost identical:

Note: I will go into more detail on what cleaning solution to use later on in the post, but you can use fragrance-free dishwasher soap which is quite easy to find and affordable, or you can also use OxiClean, which also works well for sanitizing.

  1. Prepare the “Cleaning Solution”: In a bowl where the airlock can easily fit into, pour in some warm/hot water and add a cleaning agent such as fragrance-free dishwasher soap. A tablespoon of it should be more than enough to get the job done. Mix until fully combined.
Recommendation: Put the cleaning agent into the bowl first and then pour water on top of it.
  1. Remove and take the Airlock apart: This is a fairly simple and obvious step, but depending on the type of airlock you’re using (3-piece or “S-shaped”) you need to take it apart to be able to better clean it. 

Important Note: If your airlock has overflown and you’re cleaning it while there’s still beer in the fermenter, either put a new one in as soon as possible or cover up the hole on the lid with aluminum foil to keep oxygen and strange particles from getting in.

  1. Place the airlock in the cleaning solution: Place all the parts of the airlock (lid included) in the bowl that has the previously mixed cleaning solution in it and leave it there for 30 minutes. If the airlock has been dirty for a couple of days and has a lot of gunk stuck to the insides, it might be a good idea to leave it in the cleaning solution for the entire night.
Note: My airlock is clean since I did this for demonstration purposes only.
  1. Scrub or Shake the Airlock: With S-Shaped airlocks you won’t be able to scrub them on the inside since they are so small, but you can definitely fill them with water and shake- or swirl them in order to help any unwanted stuck particles to come loose. Although it might be worth mentioning that if there are still some visible particles stuck to the inside of the airlock, you should let it soak for a little while longer.
  2. Use water to flush out the gunk: Once the airlock has been soaking in hot water and all of the gunk has loosened up, place the airlock under the tap in order to push out all of the dirt with fresh water.

The best type of Cleaning Agent to use

There are multiple cleaning agents out there that you can use, and all of them are readily available in supermarkets and are quite affordable.

I’d recommend the following:

  1. Frangrance-free dishwasher soap: If for some reason you didn’t clean an overflown airlock for a couple of weeks and you can see serious amounts of gunk, or even mold, in it, then this is probably the best way of dealing with it. Like I previously mentioned, just put about a tablespoon of the dishwasher soap in a bowl, mix it and then place the airlock in it. I’d recommend leaving it overnight if it’s got a lot of gunk in it. You can also use this method to thoroughly clean your bottles, even if they have mold.
  2. PWB Cleaner: This is another cleaning agent specifically designed to deal with thick and caked-on organic soils that are generally hard to reach and clean, and it works really well.
  3. Peracetic Acid: Peracetic Acid works as a cleaning agent where the degree of soiling is light, and it also works as a disinfectant. 
  4. OxiClean: OxiClean isn’t as effective at removing thick organic soils as PWB or dishwasher soaps are, which is why I wouldn’t recommend it to clean an overflown airlock that has been sitting there for weeks. However, it’s still effective at removing gunk and dirt, especially if it’s not that difficult to remove, plus it also sanitizes the airlock.

Depending on how “dirty” the airlock is, you might want to use one or the other. If you need to remove some serious amounts of gunk, I’d just go with PWB or the Fragrance-free dishwasher soap, and if you don’t need to deal with a lot of organic soils, then OxiClean and Peracetic Acid work extremely well.

Can you use bleach to clean an airlock as well as a blowoff tube?

You can use bleach if you don’t have access to either of the cleaners I mentioned above, and you can do so by using between 4 and 16ml of bleach in 1 liter of water and letting it soak until the gunk completely disappears (24hrs should be more than fine for this).

It’s worth noting that you should buy bleach that doesn’t come with any additives/aroma. Lucky for us, this generally means buying generic and cheap brands.

Note: Some people say that if you use a very small amount of bleach (about 4ml per liter of water), there’s no need for rinsing, but I would recommend doing it just to be 100% safe and to then use a non-rinse product for sanitizing.

Cleaning a Blowoff Tube

Cleaning a blowoff tube is identical to cleaning the airlock since all you need to do is submerge it in hot water that has any of the cleaning agents I previously mentioned, and let it soak for a couple of hours.

After this, simply rinse it with hot water and you’re done.

As far as cleaning goes, that’s about it! However, cleaning is only half of what you need to do, and sanitizing the airlock is next.

However, how important is it to sanitize the airlock? I mean, it’s never even coming into contact with the beer, so why bother?

Do you need to Sanitize the Airlock?

The airlock is responsible for keeping the inside of the fermenter separate from the outside, allowing oxygen and Co2 to be pushed out but not allowing oxygen or any strange particles to come in. It essentially works as a gatekeeper.

Now, the main reason that airlocks are sanitized is so that if the fermentation is too vigorous and the fermenter ends up overflowing, once the Krausen begins to drop when fermentation is nearing completion it will take whatever bacteria or strange particles might have been in the airlock with it, which may contaminate the beer.

You should also always put sanitized water inside the airlock and not just tap water. This is especially true when brewing in a fermentation bucket and trying to move it since picking it up allows the bottom of the bucket to give and bend slightly which creates a vacuum inside the fermenter and sucks in some of the airlock’s water (yes, that happened to me the first time I brewed). 

If any of these two scenarios happen to you and the water inside the airlock is sanitized, then your brew will probably be ok, but if you put tap water into the airlock, then you risk contamination and infection.

What Sanitizer to use?

Just like with the cleaning agents I mentioned above, there are multiple sanitizers out there you can use and most of them can easily be found in supermarkets and grocery stores and are dirt cheap.

I personally use OxiClean, but here is a list of the ones you can get:

  1. StarSan: StarSan is probably the best-known sanitizer in the brewing industry since it’s really easy to use and doesn’t need to be rinsed out.
  2. OxiClean: OxiClean is an extremely cheap cleaning and sanitizing agent (buy it once and it will last for years) that doesn’t need to be rinsed out since it’s not harmful to you or the brew.
  3. Bleach: Bleach is the most readily available cleaning & sanitizing solution out there, plus it’s super affordable. To make the sanitizing solution add 1 tablespoon to 1 gallon of water (4ml per liter) and let the items (airlock in this case) soak for 30 min. Rinsing is not “necessary” but I’d still recommend doing it with boiled water.

As I mentioned, I use OxiClean since it costs like $5 and allows me to sanitize all my equipment, bottles, tools, etc., and lasts me for over a year since you only need like a teaspoon per liter of water.

How to Sanitize an Airlock

Sanitizing an Airlock is far simpler than thoroughly cleaning it since all you have to do is put it in a bowl of water with a little sanitizer and let it sit there for 5 minutes, and that’s it!

It’s also worth mentioning that you should fill the airlock with that same sanitized water and not use tap water, just to be on the safe side.

If all else fails, buy a new Airlock

The truth of the matter is that airlocks are cheap… really cheap, and they tend to break or get damaged, etc. If you can’t find a way to actually clean the airlock properly (even after using a strong cleaner like PWB and letting it soak for a day), then I’d advise getting a new one since the risk of contaminating your beer is not worth the extra $10 an airlock costs.

Of course, you shouldn’t really just have the one airlock since if something were to happen during fermentation, you wouldn’t have a replacement one. 


I think I made it clear that Airlocks are absolutely essential tools when it comes to homebrewing if you want to be able to do it successfully, and properly cleaning & sanitizing them is a must.

Luckily, it’s a very simple and easy process and you shouldn’t have any trouble with it, and if for some reason you can’t get all of the organic soils out of it, then simply buy a new one since they are dirt cheap.

I hope this information was useful!

Have a great day!

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