Geoffrey Wiseman

Kaffeologie S Filter for AeroPress

When you make coffee in an Aeropress, you use a filter on the end of the press which prevents the coffee grounds from going into your cup. These filters are cheap, plentiful, and use very little paper, so there are limited reasons to switch to something else.

However, when I make coffee with my AeroPress at one of my client's offices, I do sometimes forget to bring a filter from my desk to the café. This could result in a trip to my desk and back while the coffee is brewing, throwing off the timing of the whole affair. It's not a big deal, but it did make me consider the value of a re-usable filter.

So when Kaffeologie kickstarted its S Filter for Aeropress, I backed it. Some months later, it shipped.

UPDATE: Incidentally, they have a new version of the S Filter; this review covers my first-generation edition. I will be getting the second-generation one, and I may review it later.


The S Filter cost $10. That's pretty cheap, but the paper filters that come with the AeroPress are surprisingly affordable. That means the S Filter costs about the same as two 350-count packs of filters, or 700 filters.

Build Quality

The S Filter seems neither delicate nor robust. There's a metal disc that provides most of the structure which is bonded (welded?) to a fine metal mesh that filters the coffee. The mesh's bond is near but not all the way to the mesh edge, which means there's a small flap of mesh you can lift. This seems like it might be prone to putting some strain on the mesh over time.

You can bend the disc if you're not careful with it; that's probably inevitable given that it has to be so thin, unless it were made with very expensive materials.

It is neither as strong as I would really like it to be nor as flimsy as I might have feared it could be.


The AeroPress' design expects a very thin filter at the end of the press. The S Filter's metal is thicker than the paper, and as a result, you can't screw the press' cap on as tightly with the S Filter as you can with a paper filter. However, I didn't find that to be a problem. The cap can be screwed on enough to ensure a secure fit.

Basically, it's not a perfect fit, but you aren't likely to have a problem with it.


The AeroPress is forgiving and makes good coffee over a wide variety of conditions. I don't find the S Filter changes that very much in either direction. I don't notice a significant difference between coffee made in an AeroPress with the S Filter or a paper filter.

It might be worth noting that lots of people (including Kaffeologie) talk about the 'paper taste' of paper filters, and that's something that I have never really noticed or paid attention to. Perhaps if I did a side-by-side comparison between the two, I might, but I have never made a coffee with a paper filter and thought "Boy, I can really taste the paper on that one."

The S Filter lets through more "fines" than the paper filter, so there will be a little residue in the bottom of your cup, but it's a very small amount.

If you're only interested in the coffee taste, I don't find the S Filter to be a noticeable improvement. If you're interested in the S filter for other reasons, I don't find it to result in noticeably worse coffee either.


When I ran out of paper at home, I put it into service as my primary filter to see what I thought about it. That was about six months ago.

This morning, I discovered that the metal filter was separating from the disc. As of this point, the mesh is separated around about half the disc's circumference. It still holds in place, and as long as I'm careful, I can still get a perfectly good cup of coffee out of it, but it's clearly on its last legs.


The S Filter apparently has a lifetime guarantee, so despite the fact that my filter is dying, I may be able to replace it free of charge. I'll be contacting Kaffeologie about this shortly.

I got a response quickly from Kaffeologie, who will replace the filter under their guarantee. They have apparently updated the design so that it has two rings with the mesh between it, which makes it less likely to suffer the same fate as my first-generation model. I haven't received the replacement at the time of this writing, but the response was such that I have faith.

The replacement filter arrived quickly (they even sent it to where I was staying away from home). It does indeed have a different design. I'll try to remember to review it after I know how it holds up over time. They definitely seem willing to stand behind the product, which I appreciate.


I have found that storing the filter inside the press cap is a good way to keep it out of harm's way. The rim protects the disc from bending, and the end of the cap prevents anything from poking the mesh and putting strain on the bond between the mesh and the disc.

Also, I'd noticed the filter tends to come off cleaner with the AeroPress puck had cooled a little, and I see that Kaffeologie agrees.

In Summary

Basically, I have no real complaints with the S Filter, but neither would I strongly recommend it. The coffee is the same, or close enough. The S Filter has a higher initial cost but would eventually be cheaper, albeit, only by the very small cost of paper filters.

If you find using and replacing paper filters a bit of a pain, it might be worth a try, but AeroPress filters are so cheap and plentiful that I suspect the paper filters are the right choice for most people.

If the S Filter appeals to you, I would by no means warn you away. But if you're on the fence, if the paper filters seem fine and you're not that curious to try the alternative, I don't think you'd find the S Filter to be a revelation.