Coava Coffee Roasters, Coava Kone (K-ONE) Pour Over Filter


Update: Coava Barista Wins 2011 USBC NW Regional Brewers Cup Using Kone Filter

Update: The Coava Disk – Stainless Steel Aeropress Coffee Filter

Keith Gehrke humors me with an in-depth discussion about his soon-to-be-released metal pour over filter named the Coava Kone. Known as the K-ONE in its earlier stages, the filter is based on the common Melitta paper filters used for most pour over brewing. Keith calls it a “selfish project” that he started on his kitchen table in November of 2009. He set out to create a sustainable pour over process that also produces a better cup of coffee.

Kone Coffee Filter Coava

His initially attempt was a reusable filter that mimicked the brew process of paper filters. After some kitchen-table theorizing he realized paper filters didn’t produce an ideal brew because the wet paper would hug the sides of the glass, restricting water flow to the tip of the filter and creating points of over- and under-extraction. Keith overcame this problem by redesigning the metal filter to taper quicker than the filter’s glass holder. The filter only touches the glass sides at its crown, at the very top of the Chemex holder. This holds the suspended filter away from the glass sides, allowing a free flow of water through the entire surface area of the filter and not just the tip.

The design is entirely custom, and the CAD drawings were drafted by a local engineer and submitted to a manufacturer on the East Coast. The stainless steel is sourced from Ohio and the filter’s holes are created by photochemical etching. The process creates a taper in the holes; the holes are bigger on the outside and smaller on the inside. This prevents clogging and makes cleaning easier. Only a few filters are cut from one sheet of steel, so Keith created several different versions of his design and ordered up a small test batches for each redesign.


Keith holds two filters up to the light. I can see that one allows more light through than the other. On closer inspection, one filter’s holes are closer together than the other. This is the difference between the 6th and 7th versions. Earlier versions featured a gradient of holes that were less dense at the top and denser at the bottom. The changes are made to control the speed that water exits the filter at any given location, brewing the grounds evenly and extracting all possible oils.

Matt and Keith have hit a good balance between the high acid light roasts that are currently in vogue around Portland and the darker roasts that appeal to the broader coffee drinker. It’s nice to see them experimenting with brewing technology and growing coffee plants. Their tasting room on Grand Ave is well worth the trip.

Tentative Release & Price: Late October 2010, $50

Buy the Coava Kone directly from Coava Coffee

See also: Matt Higgins – Growing Coffee & Able One-Cup Sneak Preview


Press Release:

PORTLAND, Oregon—October 25, 2010—Coava Coffee Roasters today announced that the Coava Kone, the first reusable stainless steal coffee filter for the Chemex coffee maker, is available for purchase through their website.

“We have been working on this filter for almost a year now and we are excited to finally offer it as an alternative to paper filters,” said Keith Gehrke. “It gives users of the Chemex a reusable brewing option and produces a superior cup of coffee.”

The filter is cut from stainless steel sheets sourced from Ohio. The holes are made through a process called photochemical etching. The filter is held away from the Chemex glass so that liquid can pass through at all points of the filter instead of just the tip.

The filter is available through Coava for $50 and fits standard Chemex coffee makers.

Coava Coffee Roasters roasts and brews coffee at 1300 SE Grand Ave. Portland, OR 97214. Coava leads the NW roasting community with its highly regarded single origin selections sold in custom-embossed bags. Their showcase café opened in a shared space of Bamboo Revolution last Spring.

Keith Gehrke joined Coava’s Owner, Matt Higgins, in January of 2010.

Press Contacts:
Keith Gehrke
Coava Coffee Roasters
(503) 894-8134

10 Responses to “Coava Coffee Roasters, Coava Kone (K-ONE) Pour Over Filter”

  1. Charles Tremewen says:

    I want one when you get them…. Love the sustainability of it and the possibility of not be tied to those huge Chemex filters all the time. It’s a different taste and not as rounded as the Chemex filtered coffee but a nice alternative. Contact me when you have one for sale. You are onto something here!


    • smb says:

      Fantastic! I would like to purchase one as soon as it is available. Great job, Matt and Keith!
      I would like to critique the following comment: “Matt and Keith have hit a good balance between the high acid light roasts that are currently in vogue around Portland and the darker roasts that appeal to the broader coffee drinker.”
      Light roasts do not appeal only to people around Portland. If you examine the preference of coffee professionals the world over, I think you will find that the vast majority eschew dark roasted coffees. But light roast preferences are not limited to coffee pros. Many consumers the world over are leaving burnt beans behind.

      • robert says:

        hah! most of the coffee drinking world(turkey, greece, most of africa, etc.) prefer dark roast coffee. real coffee drinkers want the mahogany, earthy taste. not some insipid north american wishy washy taste. much like beer. guess the northwest likes light watery beer?

        • Sondre says:

          I guess it’s not about light and watery, but as in light roast to bring out the actual tastes from the coffee itself, the product of the sweet, acidic, delicious coffee berry, not to leave tastes of the process in the cup. Much like is happening with beer and micro-breweries bringing out the tastes of the raw material. I’ll take complexity, nice acidity and natual sweetness over burnt, woody, nutty any day. Also, if you look at the right raw material, you can easily find a dark chocolate, nutty, woody, dense coffee that is the product of origin (india?) that still has a lighter roast to bring out those flavours.

          Oh, and loving the Kone, got one in the mail and it rocks my world these days (:

  2. Swimming Willamette says:

    I’m looking forward to the Kone also. I didn’t know about Coava, but walked in spur of the moment hoping they had a solid coffee maker. The Kone is pretty much the pneultimate. Stainless steel, simple, local, done. I think a flat bottom (aka blunted tip) would be easier to clean, but that is just a guess. Way to go Portland.

  3. Gary F. says:

    Re: Swimming Willamette
    You do realize penultimate means “next to the last”, not the “pinnacle” or “ulitmate”. It’s more the “second to the best”.

    Sorry, just drives me crazy when I see that. As far as the filter goes, it looks great and I’m glad to finally see a sustainable pour-over filter hit the streets. I’ll be looking to pick one up.

    • lmyya says:

      I’d like to ask the poster of the now-antepenultimate comment in this mini-thread how the Kone has worked out for him or her so far. I have one, and I agree that its sustainability is super awesome (that’s Latin for “above the awe-provoking things”). But the taste of my coffee is not quite as clean, from the Kone, as it was when I ran a Hario paper filter over a little pour-over tea strainer into a cup (I know, lame hobo person, but one must make do with something). Do you find the same, or am I doing it wrong? I want to like the non-paper version best.

  4. Chas says:

    The article didn’t mention anything about how the actual end product tastes. I would imagine that this filter would not be able to achieve the ‘clean’ taste when using the paper Chemex filter. On the flip side, my hunch is that the coffee using a K-ONE is more full bodied than a Chemex.

    • Patrick E. Martin says:

      The coffee that comes out of a Kone is pretty spectacular; it has a great body, like a French Press, but without the sediment- they let the coffee sit in the Chemex for a moment after brewing to allow the fines to settle, then pour slowly out and let a small portion of the final brew (with all the sediment) remain in the glass. Over all, some of the best brewed coffee I’ve had in my life, even better than a vac-pot, which can run up to 6x the price of a pour-over at Coava (though I guess it’s hard to compare brewing methods used for different coffees.)

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