I've heard about Aeropress seals wearing out and leaking. But mine is the opposite. It's so stiff and sticky that it requires a huge amount of force to press even when the Aeropress is empty. It was unusually stiff and hard to push when I bought it but has become a lot worse over time, mostly sitting on the shelf as it's my travel brewer. I used it recently for the first time in a long while and found it basically impossible to to even insert the plunger. I had to add a trace of vegetable oil to the seal. I bought the Aeropress just before they switched to silicone.

Does anybody have an idea of how to attempt to remedy this?

Mr. Adler's solution for stiff (old) seals was Chapstick. One has to keep re-applying it, though.

The new seal just works.

If you don't want to buy a new seal, you could try leaving the plunger installed in the tube for a few weeks and see if squishes it smaller. I've had that happen before....

You might also try soaking the seal in hot water. I find that can help it become more pliable. I also go long periods without using mine, and it gets too stiff (sticky?).

Thanks for the suggestions. I guess I'm not the only one to have had this problem. Even Alan!

Chapstick: It obviously isn't toxic. And the seal doesn't have to touch the water (although I often brew inverted and press all the way to the puck). For that matter, the old elastomer seals start smelling like on old tire after a while anyway. But chapstick is temporary and there is some potential for it getting into the coffee.

Soaking in hot water: I assume you mean each time, not as a permanent fix. I'll try it. It's the easiest. And it's clean.

Leaving the plunger installed: I don't want the seal to shrink. I want it to have less friction. When lubricated it fits just fine.

Buy a new one: Yes, of course, the obvious solution. Made better by the fact that they finally (finally) switched from stinky rubber to silicone. I would have done this already but balked at the $8 price tag.

You just need a very little Chapstick on the very edge of the seal and then wipe off all the excess. I did it for a few years; never noticed anything. It is mostly white petrolatum (vaseline, etc.)

I guess if you could go for blueberry flavor for ethiopians .

I bought chinese Aeropress clone at half price of original and it also had a bit stiff rubber seal

I just used a very fine sandpaper (for metal) to decrease the seal edge diameter by something like 0.1mm or so ... took a few minutes

Just take care not to overdo it

I tried soaking in boiling water for a couple minutes. It helped a little but it was still pretty stiff.

Somehow the Chapstick thing still sounds gross to me. I'd just as soon smear a little vegetable oil on it. At least that's considered food.

I tried sanding it. I ended up reducing the diameter by 0.7-0.8mm. It's a little better but still really hard to press. I don't want to sand it any more. I wonder if I have an outlier in terms of the seal diameter or if it's just really stiff.


Can someone measure the diameter of an Aeropress seal and let me know what you have?

Yep, my 20yr old aeropress did the same thing. Rubber seal was stiff and had an oily look on the surface. Tried several things and gave up. Ended up buying a completely new one, which is also BPA free. The old one wasn't.

EDIT: correction: ~16yr old aeropress. feels like 20 years...