The Fellow Prismo AeroPress Attachment – An Honest Review

Looking to up your AeroPress game? While the AeroPress is a nifty and outstanding device on its own, you can elevate its functionality with a variety of ingenious accessories. One such accessory—i.e., the Fellow Prismo— promises to brew intense espresso-style coffee using your Aeropress.  Is this really possible? Read on for our unbiased review of the Fellow Prismo. 

What Exactly is the Fellow Prismo—and How Does it Work?

Although the AeroPress is marketed as a versatile device capable of creating espresso coffee, it can’t achieve the high level of pressure that an espresso machine does.  This pressure produces the characteristic intense, creamy taste of espresso. In an attempt to bridge this gap, Fellow—a manufacturer of coffee gear—came up with the Prismo. According to the manufacturers, the accessory increases the brewing pressure with the hopes of producing something more closely resembling espresso.

The Prismo is essentially an AeroPress attachment that replaces the original plastic basket cap and paper filter with a pressure-actuated valve and metal filter, respectively. The one-way valve prevents coffee from flowing through until there’s enough pressure in the brew chamber. When the desired level of pressure is achieved, the coffee is forced through an 80-micron reusable metal filter. This creates a long-lasting crema and a cup with a fuller mouthfeel and body – at least hypothetically.

Speaking of stainless-steel filters, they tend to attract heated debate among coffee enthusiasts. Proponents argue that they’re eco-friendly and have a small environmental footprint – i.e., they eliminate paper waste.  Detractors prefer the crisper taste produced by the paper circle filters.

The Prismo’s valve has a relatively small opening—allowing for the production of the pressure necessary to pull concentrated “espresso-style” coffee. While this coffee does not entirely compare to espresso from a modern espresso machine, it comes closer than can otherwise be produced by an Aeropress.

The accessory retails at $25 or £20—about as much as the AeroPress itself.  Let’s dive a little deeper in an effort to inform whether this is a good investment for you.

Our “Espresso-Style” Brewing Experience

In our review of the Prismo, we decided to get a little sciencey with our approach. To mitigate the risk of bias or a placebo effect, we staged a blind taste test experiment.

In our experiment, we brewed three cups using the same coffee using different Aeropress techniques. The first espresso sample was brewed using the regular AeroPress method—as intended by the AeroPress inventor, Alan Adler. The second sample was prepared using the widely popular inverted AeroPress method, while the final cup followed the Prismo’s espresso recipe. 

Our taster did not have a clue regarding the brewing methods used to create each cup to ensure that his verdict was as honest as possible. But before we get to the “research findings,” here’s a brief overview of the unboxing and the Prismo’s espresso-style recipe. 

Fellow Prismo’s Recipe

Our Fellow Prismo came with two parts; the valve and a metal filter. The accessory also comes with an instruction manual/guide on how to brew espresso-style coffee.

The metal filter—which comes inscribed with the “Fellow” logo—nestles perfectly inside the adapter housing the pressure-actuated valve. This entire Prismo assembly is then fastened onto the AeroPress in an upright position. As advertised, it seals tightly with little-to-no leaks.

Our recipe was based on that provided in the manufacturer’s manual.


  • Fresh coffee – Fellow recommends finely-ground espresso-blend (dark-roasted beans). In our test, we used Taylor’s Lazy Sunday (3 Roast, Gentle, and Easy-Going Ground).
  • Water – 50 ml at 212 degrees Fahrenheit (100 degrees Celsius)
  • Fellow Prismo
  • Espresso Cup/Demitasse
  • AeroPress


  1. Attach the Prismo to the AeroPress.
  1. Add the 20 grams of coffee into the chamber.
  1. Pour the boiling water slowly into the AeroPress for around 10-20 seconds.
  1. Stir the coffee mixture for up to 30 seconds to increase the extraction.
  1. At the 1-minute mark, hold the AeroPress on top of the espresso cup and forcibly push the plunger. After the initial press, maintain the pressure to push the shot into the cup.

For a recipe guide of the other two AeroPress brewing techniques (i.e., the regular and inverted methods) please check out our guide to the Aeropress!

Blind Taste –Was the Prismo Espresso Any Good?

As highlighted earlier, we brewed three cups—each using a different method but the same ingredients. The aim was to determine whether an espresso-style cup brewed with the Fellow Prismo was really different from coffee brewed through the regular or inverted method. So, how did the blind taste go?

  • Regular AeroPress Method Tasting Notes: The first cup our taster sampled was brewed using the regular AeroPress technique. It had a rich and nice aroma, with hints of dark fruits, berries, and red currants. As for the flavor profile, it was strong (but not too bitter)- smooth, nice, and delicious. It was a bit tart but not overpowering. Generally, it was nicely balanced with notes of dark chocolate, cranberries, and no unpleasant smokiness.
  • Inverted AeroPress Method Tasting Notes: This brew has a similar aroma to the first sample, but a bit smokier. It also had hints of sweet fruit or chocolate. The tasting notes were noticeably fruity, much more bitter, and more full-bodied. Unlike the first sample—which was mellow—this cup was rather strong.
  • Fellow Prismo “Espresso-Style” Tasting Notes:  The final cup had a beautiful dark chocolate aroma, nice, sweet, and not too much fruit. The flavor was slightly ‘vinegary’ and quite sharp. You could also feel a rougher texture or graininess— this may have been some grounds escaping the filter. Overall, it was a decent cup of coffee but did not have a flavor profile quite as good as that produced by the other methods

With the experiment completed, it was time to reveal the ranking of the three coffee. The best cup was…drumroll…

  1. Inverted AeroPress – WINNER
  2. Regular AeroPress – 2ND
  3. Fellow Prismo – 3RD

Unfortunately, the Prismo was rather underwhelming—even in comparison to the regular AeroPress method. Maybe the measurements (20 grams coffee: 50 ml water) in the recipe were a bit off- changing the ratio is probably worth exploring

Verdict – Does the Fellow Prismo Deliver as Advertised?

Well, yes and no! Our opinion was divided owing to the precarious balance of pros and cons. The Fellow Prismo is an exceptional and innovative device—and there are areas where it shines. But it also fails to impress in other areas. Below is an overview of our “pros and “cons” of the Fellow Prismo.


  • Pocket-Friendly: A $20 adapter that turns your AeroPress into a miniature espresso machine is a win.
  • No-drip filter: One of the most cumbersome parts about the inverted AeroPress method is the risk of making a mess in your kitchen. But with the no-drip filter, you’re assured of minimal leaks during brewing.
  • Comes with a metal filter: The Prismo is a decent way of owning an otherwise pricey metal filter for your AeroPress. 
  • Versatility: It can be used for full immersion, cold brew, iced teas, Americanos, and more.


  • Cleaning: Although the manufacturer’s guide claims that the Prismo is easy to clean, our experience with the attachment suggests otherwise. Any AeroPress accessory that takes away the joy of how easy it is to tidy up afterward is a real downer.
  • Portability: Sure, the AeroPress and the Prismo are portable as they are. But making a good “espresso-style” cup demands careful measurements and ratios that can only be achieved with corresponding equipment such as a scale, thermometer, etc.
  • Concerns surrounding the risk of shattering delicate cups while pushing the shot.
  • The filter is rather thin and bendable—raising questions regarding its durability.

Jay Arr

Jay Arr is passionate about everything coffee. What began as a simple interest in the history, production, and brewing of coffee led him to a job as a barista at a national coffee chain. That’s not where Jay’s story with coffee ends, however. Roasting and brewing day in and out, he continued to gather knowledge about all things coffee.

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