Why is Your AeroPress Not Sealing? And How to Fix

By Evelina •  Updated: 07/09/22 •  7 min read

If you’ve been using your AeroPress for at least a few months, you’ve probably noticed that the plunger doesn’t always seal perfectly. This can be annoying, especially if you’re trying to make a quick cup of coffee before work.

The truth is, there are a few different reasons why your AeroPress might not be sealing properly. And the worst part is, if you don’t know how to fix it, your coffee will suffer.

So today, we’re going to show you why your AeroPress might not be sealing, and how to fix it. Let’s get started!

Reasons Your AeroPress Is Not Sealing

There are three main reasons why your AeroPress might not be sealing properly:

1. The Rubber Seal on the Plunger is Compressed.

2. The Plunger has Stiffened Over Time.

3. Coffee oils have built upon the seal.

The rubber seal is the most likely reason why your AeroPress isn’t sealing. When the rubber seal becomes compressed, it can no longer create a tight seal. The seal is made out of silicone, so if you’ve had your AeroPress for a while, it’s possible that the rubber seal has simply become too old and needs to be replaced.

On the other hand, if the plunger has stiffened over time, it can also cause problems with the seal. AeroPress plungers are made out of plastic, which can become brittle and break over time.

Coffee oils can also tighten the seal on the plunger, making it difficult to press down. These oils are natural and come from the coffee beans themselves. Over time, they can build up and make the seal tighter.

Important: Since the seal is made out of rubber, it’s important not to use it with boiling water. The official AeroPress website suggests a temperature of 175 degrees Fahrenheit. If you use boiling water, the seal will likely break and you’ll need to buy a new one.

How to Seal Your AeroPress

Fortunately, there are a few things you can try to get your AeroPress sealing again. Although it might take a little bit of trial and error, you should be able to get your AeroPress working like new again in no time!

1. Use Mineral Oil.

I know this sounds a little bit confusing, but trust me – it works! Mineral oil is a natural lubricant that can be found in pharmacies. It’s safe to use with your AeroPress, and it will help to expand the rubber seal, making it easier to create a tight seal.

What you will need:

How will this work? That’s where the microwave comes in. First, make sure your seal is fully cleaned and dry. Next, take a small gentle brush and apply a thick layer of mineral oil to the rubber seal.

Once you’ve done that, take the rubber seal and place it in the bowl. Then, add 1-2 tablespoons of water to the bowl and add the small plate on top to cover it.

Now, place the bowl in the microwave and heat it for 1 minute. Do this 4-5 times, but always make sure to check the rubber seal in between heating it up. You don’t want to overheat it and damage the rubber.

TIP: Don’t use cooking oils like olive oil or vegetable oil. These can damage the rubber seal. Mineral oil is the best choice.

2. Brew Inverted.

AeroPress inverted

If you are not familiar with the AeroPress inverted method, it’s basically when you brew your coffee with the AeroPress upside down. When you do that, it allows all the coffee grounds to be fully saturated, which results in a richer cup of coffee.

It might sound a little bit complicated, but it’s actually quite easy to do. All you need to do is turn your AeroPress upside down so that the plunger is at the bottom. Then, add your coffee grounds and water as usual.

By doing this, you will be able to evenly distribute the coffee grounds and it will be easier for the rubber seal to pass through the chamber.

3. Store the Seal Separately.

Caring for your AeroPress rubber seal is important if you want it to last. One way to do that is to store the rubber seal separately from the AeroPress plunger. You can do this by simply taking the seal off and storing it in a dry, safe place.

This will help to extend the life of the rubber seal and make it easier to create a tight seal when you are ready to use it. One other thing you can do if you want to store the AeroPress altogether is to press the plunger all the way down. This will help to keep the seal from being compressed.

4. Replace The Rubber Seal or Get A New Plunger.

If you’ve tried all of the above and your AeroPress is still not sealing, then it might be time to replace it or get a new plunger. The rubber seal costs around 10 dollars, while the plunger costs 15 dollars.

If you’re not sure how to replace the rubber seal, you can check out this video.

Why Is Your AeroPress Leaking?

If your AeroPress is leaking from the bottom, there are a few other things that can play a role in that. One possibility is that the seal on the plunger is not seated correctly. If this is the case, simply remove the plunger, check that the seal is in place, and add the plunger back into the chamber.

Another possibility is that you are using a coarse grind. If the grind is too coarse, the water will pass through the coffee grounds too quickly and not extract all the flavor. Try using a finer grind of coffee and see if that solves the problem.

Important: If your AeroPress is leaking when you try to make coffee with the Inverted Method, make sure the filter cap is screwed on tight. If it’s not, the water will leak out when you try to turn the AeroPress over.

When to Replace AeroPress

If you tried everything we talked about and your AeroPress is still not working properly, it might be time to replace it. The good news is that AeroPress is a very affordable coffee maker, so replacing it will not break the bank.

We already talked about the price of the rubber seal and plunger, but the other replacement parts are also very affordable. For example, both the filter cap and the chamber cost 10 dollars each, so you can easily replace them without worrying about the cost.

Read Also: 21 AeroPress Tips and Tricks to Step Up Your Game

Frequently Asked Questions

aeropress not sealing

How to Replace AeroPress Seal?

To replace the seal on your AeroPress, you’ll need to first remove the old one. This can be done quickly with your fingers or a small tool. Once the old seal is removed, add the new seal and press it so that it is seated correctly.

How Long Does AeroPress Seal Last?

The AeroPress seal can last for up to 3 years. However, if you use your AeroPress to make coffee multiple times a day, you might need to replace it sooner. Using boiling water can also shorten the lifespan of the seal.

Does AeroPress Wear Out?

Typically your AeroPress won’t need to be replaced. The only thing you might need to replace is the rubber seal since it’s the only part subject to wear and tear.

Why is AeroPress Dripping?

It’s actually very common and normal for your AeroPress to drip a few drops of water before you press with the plunger. Since your AeroPress sits in immersion for a few minutes, this allows some water to seep through the grounds.

Last Thoughts

So, if your AeroPress isn’t sealing and coffee is leaking all over the place, don’t worry. You can fix it! We hope this article has shown you how to seal your AeroPress properly and given you a few tips on why it might be leaking in the first place.

As always, if you have any questions or need help with your AeroPress, feel free to reach out to us. We love talking about coffee and would be happy to help you get the most out of your brewing experience. And don’t forget to get our free grind size cheat sheet to help you improve your coffee brewing skills!


Evelina’s passion for coffee could never been hidden. Having worked as a barista, she learned the true value of the coffee bean and its secrets. As she continued to evolve as a barista, so did her knowledge, techniques on making different coffee blends and most importantly how to operate every kind of gear when it comes to coffee. Having a degree in biomedicine and being a barista, allows her to provide our community with in-depth knowledge surrounding the topics of coffee.

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