If you find it difficult to smoothly plunge your Aeropress, the common reasons are using store-bought coffee grounds that are very fine, not performing agitation at proper intervals, problems with the rubber seal in the piston because of poor maintenance, poor choice of filters or problem with your coffee grinder.
I use my Aeropress sporadically and noticed recently that the rubber seal gets harder if I don’t use it often. I went down the rabbit hole trying to investigate this issue and compiled this guide.
| Change grind size | The number 1 problem with Aeropress not plunging properly is the use of incorrect grind size. The choice of grinder will have an impact. If you grind the coffee too fine or prefer store-bought coffee then choose a different technique like inverted brewing. |
| Change rubber seal | Another common issue that affects plunging. The rubber gets worn out(or hard) if not cleaned properly. Get a replacement rubber seal and fix this issue quickly. Otherwise, time to replace your Aeropress. |
| Change filters | If you use metal filters, try plunging with a paper filter after wetting it with 2 to 3 drops of water. Clean metal filters regularly. Avoid double paper filters as it has no effect on the brew and can affect the plunging. |
| Agitate properly | Often, people don’t agitate at correct intervals. You should agitate twice, the first time is called blooming to release CO2, and the second time after you pour the correct amount of water. Depending on temperature of the water agitate additional times (if needed) |
Keep the recipe simple and invest in a good-quality grinder, a kitchen scale, and a gooseneck kettle for a consistent brewing experience.
Before we continue, you will see a lot of Aeropress information talking about 3 important variables. The “grind size of coffee“, “water temperature“, and “amount of coffee to water ratio”. To make it easier, these are the numbers I recommend if you aren’t following this, then try to fix the recipe and then continue
| Variable | Quantity |
| Grind size of the coffee beans | Coarse grind to a touch finer than coarse |
| Water temperature | 87°C(188,6°F) – 95°C(203°F) |
| Amount of coffee to water ratio | 1:16 coffee to water including 45-60g of water during blooming |
Grind size → #1 issue
If you find it too difficult to plunge (a.k.a press the piston to extract your coffee), the most common issue in my experience is the size of the coffee grounds. Do you use a store-bought coffee ground? Then it is the problem because these coffee grounds are finer than what an Aeropress expects.
If you have already bought the coffee grounds but still want to brew using Aeropress, try the inverted brewing technique I have mentioned in the last section.
Otherwise, I recommend changing the grind size, by opting for a medium or a grind just a touch finer than coarse. As you will read in the rest of the article, this is up for experimentation. As a rule of thumb, the coarser the grind is the milder the extraction is, but gets progressively easier to plunge.
Read Also: Best coffee beans to buy on Amazon (2024)
There are a lot of useful resources on what the “perfect grind size” is, but I don’t calculate a lot when it comes to my brew. I keep the grind between 700-800 microns.
Additionally, don’t overload the coffee grind into your Aeropress. The typical recommendation is 15-20g depending on how much coffee you want to extract with 250-300ml of water (1:15 coffee ground to water ratio) in 2 stages. Again, everything comes with experimentation, so don’t be hesitant to try your hand with different numbers.
Note that the inverse can also be true with the grind size, that is, too coarse of a grind can result in water dripping/leaking faster in your Aeropress.
Not using a kitchen scale
Having written the above section, I remembered that, the first few tries with the Aeropress were mostly eyeballing the coffee ground and water. I struggled at times to plunge smoothly while the other times it would automatically start dripping with very minimal effort.
After watching a video from James Hoffman, I realized that the missing piece was a kitchen scale! Yes, I highly recommend using a kitchen scale to track the measure of the coffee grind and water you are pouring. This improves your coffee plunge and extraction by multiple folds. Because you are measuring what goes into the Aeropress, the coffee flavor is also consistent.
Agitating the coffee
There are 2 stages when you should agitate your coffee ground.
The first stage is called blooming. Put the coffee ground and pour 45-60ml (1:3 ground to water) water and let it sit for 30-45 seconds. This stage saturates the coffee grounds and helps in the release of CO2 [reference: National Library of Science].
Once this is done, you can go ahead and pour 200-230ml of water in a circular motion and stir it gently. This allows the coffee grounds to not sit at the bottom and block the filter instead, it encourages “agitation”.
A good gooseneck kettle is my recommendation here. As i discuss in my article about Aeropress not holding water properly, if you dump a lot of water into the aeropress, it is going to quickly start dripping
If you are missing any of the above stages, then the chances are the plunging is going to be slightly difficult.
Worn out rubber seal
Wear and tear in any coffee brewer is common, in Aeropress though there is nothing important that can break. However, the rubber base in the plunger can get worn out. This can be due to dry plunging (where you plunge without any water in the chamber), or leaving the plunger inside the chamber and not cleaning it after every brew.
Clean the rubber
To begin with, try not to leave the piston inside the chamber after plunging. Remove the filter, push the puck out, remove the piston from the chamber, and clean it immediately.
The compression and chemical compounds in the coffee will “eat the rubber” over time. So if you do this repeatedly after every brew several times a week, the result is that the rubber will be damaged.
Nevertheless, after several years of using the Aeropress, I still found my rubber bottom worn out which made it extra difficult to plunge. If you are in my position, get a replacement rubber seal like the one I found
Re-hydrate the rubber
Another reason why the rubber might become hard and difficult to plunge is if you haven’t used it for a while. The solution is to take a pot of boiling water and soak it for 2 to 3 minutes. This should loosen the rubber and make it easy to plunge.
Note that, if the rubber is worn out, this will only make it worse. Investigate the rubber seal to find if there are any pieces of rubber sticking out. If not, simply put it into a pot of boiling water and you should be good to go!
A different technique I found online was to use a rubber protectant (sort of a lubricant that re-hydrates rubber tubes). I have not tried this, but be careful if you are going to use this method. Proper care has to be taken to ensure that the chemical is completely cleaned off the rubber before using it in the brewer.
Choice of filter – Metal vs Paper
Choosing your filter can have a noticeable difference in your Aeropress plunging. To begin with, a lot of Aeropress specialists recommend using a metal filter. In the long run, this is cost-saving but limits you on the type of grind you can try and can get clogged making it difficult to plunge.
Do you use a metal filter? Try switching to the conventional aeropress paper filter and notice the difference. If your grind is coarser and the water starts dripping very quickly, it is better to go with a metal filter as the default.
If you are using the paper filter that Aeropress recommends, don’t forget to wet the paper with 2 or 3 drops of water.
Avoid double paper filtering unless you are using a coarse grind. I have seen recommendations on TikTok/YouTube to use 2 papers for a better extraction. This is unnecessary if you have a good grind as this has no considerable difference in the flavor (in my opinion!)
The choice of grinder has an effect
As you might have noticed, most of the suggestions are about adjusting the “grind size” or controlling the extraction based on the grind size. The most important tool apart from your Aeropress itself is your choice of a grinder.
This article is not about grinders, but for quick readers, go for a burr grinder instead of a blade grinder if you are serious about Aeropress. If you are simply trying out Aeropress then the option is an electric grinder for 15 bucks that you can find on Amazon.
Some choices for better brew will be Mueller HyperGrinder, Oxo canonical burr grinder, or the classic Timemore C2.
Overdoing the plunging
Treating the Aeropress piston as a workout machine and applying too much pressure is not going to magically push the coffee out faster.
Apply gentle pressure, Although you might feel inclined to apply excessive force during plunging, doing so can complicate the process. It is good to apply a consistent amount of pressure to make sure the piston is not going at an angle. What could help is slightly rotating the piston (if possible).
Inverted brewing
Not for everyone, that is the reason why I have included it at the end of this list. I do not bother turning the chamber and piston up and down when brewing, because the classical method works fine if you do it properly.
The advantage however is that it helps you plunge smoothly and improves the extraction quantity because the coffee does not start dripping through the filter before you seal it with the piston.
This can give you a slight advantage if you prefer a finer grind of coffee as the only reason plunging is difficult is because the coffee grounds are sitting at the bottom faster.
Conclusion
Even though there is a science to making a great Aeropress coffee, it is a personal science, meaning you decide the temperature, grind size, and recipe to make a coffee that tastes good.
If you find plunging harder with a fine grind but want only to drink a finer grind (mostly the case if you are using store-bought coffee grounds), then agitate twice and plunge harder or experiment with coarser grinds for a better-tasting coffee.
Finally to recap, if you find it difficult to plunge your Aeropress
- Begin by investigating the coffee ground size. Is it too fine? then plunging is going to be hard.
- Investigate if the rubber is worn out or has gotten harder. Put it in a pot of boiling water or prefer buying a replacement rubber seal
- Agitate the coffee at 2 different times, one to bloom which releases CO2, and the other after pouring the water to prevent coffee grounds from reaching the bottom fast
- Stick to the recipe, and get a good kitchen scale for a better brewing experience. This prevents uneven plunging experience, sometimes easy while the other times it is super difficult.
- Confirm that the metal filter is not clogged. If you use a paper filter, ensure you add 2 to 3 drops of water to wet it before plunging.
- Invest in a good coffee grinder. Depending on a store-bought coffee ground will eventually clog the filters faster.
- If nothing works, choose the inverted brewing technique to prevent water from dripping faster and slightly ease the plunging.
