Metal filters for Aeropress

By Mick Gormley

I've road tested the Aeropress metal filter against the Concetto one - here is what I found out.

Earlier this year the makers of the Aeropress released a range of interesting new products for and variations on their iconic coffee brewer, including a metal filter which has been created as an eco-friendly alternative to the paper filter that we all know and love.  

We've stocked this metal filter in the Steampunk shop for a couple of months now, and when it arrived I was pretty sure it was set to become another valued tool in my expanding armoury of brewing kit. Regular readers of this blog may have seen a recent post about the joys of using it to make a very delicious Long Black-style coffee.

We also decided to carry an 'unofficial' metal filter disc for Aeropress made by a Glasgow-based company called Concetto (it comes in two sizes, Fine and Superfine) which I have been using for the last 18 months, with great success.

Because I LOVE to play around with this stuff (and so you don't have to) I thought it would be useful to try a direct comparison, and I have been brewing with both filters side-by-side for a couple of weeks.

The results are in!!

I was first introduced to the Concetto filters when Steampunk head honcho Cath circulated a very slick YouTube video which highlights the relative merits of the two discs with a couple of useful recipes. This scared the bejayzus out of me when I first watched it, as it looked so impossibly, impenetrably grown-up and life-styley.

To be honest, though, part of the Concetto filters' appeal IS their beautiful design - they are golden, shiny and precision-made. (As my colleague Amie pointed out, they also do a very groovy, psychedelic thing when you hold them up to the light and rub them together.) However, they also have a weight and robustness lacking in the Aeropress branded filter, which is easily bent when you are removing it after a brew (it can be bent back but will retain a slight but permanent mis-shapenness, I've found).

The Concetto discs are also carefully designed to do an efficient job in extracting coffee solubles evenly, which is essential in creating a well-flavoured, balanced brew. Each differently-sized disc has a regular pattern of tiny perforations which allow very fine particles of ground coffee and oils present in the beans to pass through and add flavour and character to the coffee.

In contrast, as I mentioned in an earlier post, the Aeropress-branded filter is actually a circular mesh rather than a perforated disc, and the holes in the mesh are a little too large to allow the brewer to be used as it was originally intended.  Water passes too quickly through the filter when using the traditional 'upright' method, and you can only get decent results by using the 'inverted' method, where the brewing chamber is positioned upside down and then flipped just before you push the plastic piston down. In fact, I've also found that, even with the inverted method, making a longer drink of say 200ml (which is probably everyone's go-to Aeropress recipe) will generally fail, as the process of flipping causes a gush of liquid through one side of the filter, giving you a very uneven extraction and a pretty rubbish-tasting brew.

Unhelpfully, the branded metal filter is also designed with decorative elements - a pattern of curved metal lines and a pointless Aeropress logo which interrupt the mesh and thereby make it impossible to achieve a totally even extraction.  This is beginning to feel like something that has been created as a desirable accessory rather than a tool to maximise your chances of making an amazing coffee! To add insult to injury the Aeropress-branded filter is marginally more expensive than the Concetto. If I'm honest it feels more comfortable supporting the upstart Scottish company, who imagined a different way of enjoying a classic brewer and made it work before the big guys decided to do it for themselves.

In summary I would say the Aeropress metal filter is good at one thing, and perhaps one thing only - the recipe that I recommended in my earlier post. Even then, the Concetto Fine disc will do this job even better!

I love this short, intense espresso-like drink, which was cribbed from a recipe promoted during the COVID pandemic by coffee guru James Hoffman. There is a similar recipe on the Concetto Youtube video I mentioned, which uses even less liquid and has a faster brew time, but I have found that the Hoffman-inspired version gives better results. It works amazingly well with our Colombian beans grown by Paola Trujillo, making a rich, jammy, smooth coffee with lingering, sweet fruit flavours that reminded me of dark wine gums!

In contrast to the 'Fine' disc and the Aeropress own-brand version, the Concetto Superfine disc is specifically suited to making a longer 200 ml drink, and as a good starting point I would recommend the second recipe below (it's a nice way to highlight our other current Colombian coffee, San Sebastian. It's a much gentler hit than the face-melter above, but has delicious tangerine flavour, delicate acidity and a chocolatey sweetness). With this technique you are swapping out the paper filter for a metal version, but not having to adapt your usual Aeropress technique too much in doing so. You do, however, have to use the 'inverted' method described above. The result will be a different experience, giving a more full-bodied drink with wilder flavours than the paper allows, but sacrificing the 'clarity' that many coffee lovers crave.  It might blow you away and you'll never use another paper filter again, or you might find that it's an alternative take that complements the brews you are used to. Either way, I still like the idea of making lots of tiny, sustainable changes that might accumulate into something more meaningful.

In their YouTube video the Concetto people suggest their own Superfine disc recipe for a long drink, which I pretty much ignored until recently, and which totally surprised me when I finally got round to trying it out.  This recipe uses a much larger dose of coffee - 30g as opposed to around 11g, which I would normally suggest. The grind size is also different (much coarser), the brew time shorter and the recipe uses less water (though you DO use the traditional 'upright' method in this instance).  The resulting, fairly concentrated brew is then diluted to taste, which I found vaguely troubling, but after a week of returning to it again and again, I'm feeling pretty close to declaring myself a total convert. This is quite a heavy dose for a coffee that you might drink by yourself (a double espresso at Steampunk typically uses 18g). I would normally use 30g coffee for a 500ml pourover, but here diluting the brew to 500ml makes a drink that is far too watery. Somewhere between a total of 250ml and 300ml works best, and makes an almost decent amount to share, though I have mostly preferred to scoff the lot myself.  I've had exceptional results with our Ethiopian beans, Nensebo. This is a fruity coffee with ripe blackcurrant flavours up front, but until I brewed the beans with this method I hadn't been able to get some of the other notes my colleagues in our roastery described. Using this method, all of a sudden the sweet lemon drops were right there!!

I've listed this with the other recipe suggestions below. As to the two types of metal filter I would say the bottom line is this: If you like official merch then the Aeropress filter could be a good choice, but otherwise I would definitely recommend shopping local and going with the Glasgow guys!

SHORT RECIPE: AEROPRESS BRANDED METAL FILTER; CONCETTO 'FINE' DISC 

Watch James Hoffman 'No Machine Required' YouTube video

LONG RECIPE: CONCETTO 'SUPERFINE' DISC