As appreciation the craft of hand-brewed, manual coffee preparation has surged in the past few years, it's no wonder that sustainable innovation would follow suit. Enter Coava, a Portland, Oregon roaster whose passion for reusability dovetailed nicely with a passion for delicate, nuanced coffee.
We spoke with Coava's Keith Gehrke about the company's two new brew filter inventions—the all-American-made stainless steel KONE (for Chemex or other pourer cone) and DISK (for Aeropress).
What inspired you to make permanent coffee filters?
I think it's just from me personally not being a fan of paper filters. I was making a lot of Chemexes at home, and, making it every day, I thought I would try the Swissgold and the Bodum gold filters and see how they worked, and see if I wanted to use those instead. So I bought both of those and used them and didn't like the results—they didn't quite brew how I wanted; they didn't really replicate enough of what the traditional paper filter brought out. Also they were made of plastic, which I thought, that's a bummer. You go from a paper filter which, if you don't rinse it (or even if you do) could taste like paper, and isn't that sustainable, and to go to plastic, I didn't really feel like I was winning at that point. So I thought, what if I made this out of stainless steel?
Why stainless steel?
Stainless steel is durable, easy to clean, and doesn't impart any taste or flavor into the coffee, if it's high quality stainless. It was also important to me to keep it all US-made—all the parts and the labor and the company that I have making the filters work with stainless all the time, with a photo etching process. I teamed up with my friend Isaac, who helped me get some rough computer drawings of a filter, and what we did was sat around my kitchen table, took a Chemex filter and traced it, cut it to where it fits in the Chemex perfectly,and came up with a rough drawing. It progressed from there to other coffeemakers like Aeropress.
Does it make a difference in the flavor of the brewed coffee?
I think it depends on who you're asking, or who's telling you what they like about their coffee! I guess someone who really loves the cleanliness, look and taste feel of a paper filter, and they don't want any sediment whatsoever, they could pick apart the KONE for sediment. But my answer is that it's a reusable filter, this is how it is. It's really full in flavor, and some have said it's sweeter, and that they like the way it ends up tasting in a cup.
For the KONE and pourover, it would be finer than what anyone uses for any paper filter, but not as fine as espresso. You actually want the coffee to be fine enough to be its own filter, if that makes sense.
Its own filter? Can you expand on that?
With reusable filters, the goal is to clog the filters. You want the holes to clog, because if you don't clog them, and you expose the coffee to too much turbulence, and have too much agitation of fine and large particles, then you're going to force all the fine particles out of the holes [and undesirably into your cup], because no hole can stop them. But if you grind fine enough and are gentle enough in your pouring, you let the grind become its own filter, that's what really creates a more restricted brew and a cleaner cup. So a finer grind results in less fine particles in your cup. It's counterintuitive, but that's what happens.
For the Aeropress, I've worked with really fine grind and a coarse grind, and each works great. The best results I've achieved are with the inverted Aeropress brew methods: you suspend all those fine grounds [in water] and you flip it, and you put the pressure on, and the filter holes are clogged. The water still goes through, but the fine particles are suspended up top.
Has roasting affected your perspective towards brewing coffee?
Yeah, since roasting, and just being in coffee, I feel like it has led me to really go down a path of experimenting. You're always thinking, oh, what would make roasting this batch better or easier, or is there another tool, so I made a device for cooling batches. I'm kind of a tinkerer, so looking into roasting has clearly affected my coffee brewing.
Keith and Coava plan to launch a new line of coffee brewing toys this coming year.