Buzz has been building steadily over the last few months around the December Dripper, a new coffee brewer from co-designers Youngmin Lee and Nicholas Cho. It's a drip cone—you've likely seen those before—but this cone comes with an adjustable brew flow aperture that promises a new degree of control over how water flows through your coffee. The end result, according to the project's new Kickstarter page—launched today— is an “an even extraction every time”, across a variety of grind sizes and recipes.

Here's more on that variable aperture from Kickstarter:

“The main innovation of the December Dripper is a variable aperture base. The ability to change the number of openings at the bottom of the dripper allows you to slow the flow of water through the dripper, consistently reaching your target brew time. In most other drippers, which have no adjustable flow control, you can only control flow by varying the amount of coffee you're brewing, or worse, by adjusting the grind away from what's optimal.”

Cho, based in San Francsico, and Lee, based in Seoul, have coffee nerds around the world wiggling. To learn more about the December Dripper, Sprudge co-founder Jordan Michelman spoke with Nicholas Cho digitally from San Francisco.

Hey Nick, and thanks for chatting with us about your new product. To start, please give us the elevator pitch for your new December Brewer: what does it do? Why is it good?

Since Sprudge readers tend to be more coffee educated than most, I’ll keep it real.

It starts with a theory: For pourover coffee brewing (a medium or light roast), the typical target brew time exists somewhere between 3 to 4 minutes. For that target brew time, there’s an optimal grind size. That means that for pourover, there’s an optimal amount of coffee you’re brewing (the ‘dose’) that will set things up for that grind and target brew time. That’s how you’ll make the best pourover coffee.

But very often, maybe even most of the time, people change things away from the optimal grind because they want to make more or less coffee than what’s optimal. That’s where the December Dripper comes in.

The December Dripper is the first flat-bottomed pourover coffee dripper with variable brew flow, which means it can make make the best coffee accessible at many different brew sizes. It’s a relatively simple concept, but the results have been fantastic.

Nick, you helped create the Brewers Cup and popularized the Kalita Wave brewer in the United States. Why launch your own product now?

The reason I developed the Brewers Cup competition and promoted the Kalita Wave brewer is the same reason we developed the December Dripper: I want to help more people to brew better coffee. At this point in my career, it makes more sense to design and manufacture this product ourselves rather than what I’ve done in the past, which is share my ideas with others who integrate them into their own products.

How did your collaboration with Youngmin Lee come about? Who else helped develop this product?

It’s just Youngmin and me, though anyone who’s designed a product will tell you that the silent collaborator is always the production factory. Youngmin and I have been friends for over 10 years, and we’re kindred spirits in many ways as our coffee careers have had a number of interesting parallels. Years ago, he told me (translated from Korean), “If you have any good ideas for new products, let me know because I know how to get just about anything made here in Korea.” So I shared with him my idea for a pourover dripper with an adjustable flow rate, and he made it happen. It’s a true collaboration in every respect.

Do you think the coffee scene in Korea is more open to innovation and new equipment, compared to in the United States?

I think that the two coffee scenes are actually very similar in that regard. People don’t always understand the science behind what makes certain things better than others, but people do know what they think tastes good. While it happens fairly slowly, the community braintrust of specialty coffee does have a way of vetting innovations and ultimately deciding whether they’re good or not. If you’ve been around for more than a few years in coffee, you’ve seen certain things come and go, and certain things stand the test of time. That’s pretty much true everywhere, I think.

We understand the product is now out in Korea, but your crowdfunding for US production just went live. Why crowd-fund this product?

Yes, the first generation product has been available in Korea for a couple of months, but it’s really more of a public beta test. Korea’s a geographically small country, so if there’s need for service or parts, you can expect availability. The Kickstarter is to fund the final development and give the barista and coffee enthusiast community an opportunity to participate in the launch. You can go to the Kickstarter page to see the rewards, but they range from the obvious December Dripper to a titanium-coated edition, t-shirts, stickers, etc.

Get technical—talk to us about the design specs of the December, and what separates it form some of the other brew cones on the market.

It starts with the brew geometry. Flat bottom geometry, like the kind you’ll find in a Kalita Wave or batch brewer, makes an even brew dynamic possible. My go-to analogy is always steak: if a butcher cut you a cone-shaped or wedge-shaped steak, how would you grill it? So much of what’s true about grilling that steak is true about brewing coffee. An uneven geometry will promote an uneven brew.

It’s made from 18-10 stainless steel, with a PTFE (similar to Teflon) gasket. Over time, we’ve found that the stainless steel version of the Kalita Wave dripper has been the most popular, because it’s less fragile than ceramic or glass and it’s less of a heat-sink (heat-absorber) than ceramic.

12 holes open or close 4 at a time to give you 4 different settings (including fully closed), that are optimized for various brew volumes. Those 12 holes are also what inspired the “December” name.

How many hours of R&D would you estimate went into this?

Between Youngmin and me, 35 years of R&D. While neither one of us is finished developing new stuff, it’s really the product of years of experience. That said, it’s been almost 3 years since the first sketches to the first production units.

Will Wrecking Ball Coffee be using December Brewers at your coffee bar in San Francisco?

Definitely.

Has there been a strong amount of interest behind the scenes leading up to launch?

We’ve gotten hundreds of messages from people who are excited about the December Dripper and are eager to see something that’s new and useful out there. Many of those messages have been from people who’ve said, “I thought of an idea like this too!” For me, coffee is ultimately about bringing people together, and I’m happy and honored for us to provide something for people to gather around, tinker with, and exchange ideas about.

Would you ever compete in the Brewers Cup using the December Brewer?

I’ve sort of pledged never to compete in Brewers Cup myself. It’d be too weird. Like incest or something.

How do you decide a product like the December is finally “done”—when does the tweaking stop? How many revisions have been done to the brewer's design?

It’s never fully done, but we’re ready for people to get it in their hands. We’ve made about 6 different prototypes and have had sketches for over 20.

From a Sprudge perspective, we've watched as batch brewing in coffee bars has enjoyed a real resurgence over let's say the last half decade. Why is a product like December still compelling in 2017?

I’ve always had batch brewers at my cafes, but while there may be a resurgence right now, nobody’s actually that excited about batch brewers. Mostly I think that people have gotten frustrated at pourover brewing and the inconsistencies and confounding variables that come with it, as well as the amount of attention they need to make the best coffee. However, there are certain advantages that pourover brewing has, especially in a home or office sort of setting, when you’re not worried about attending to a line of customers like in a cafe.

The “holy grail” of coffee brewing that doesn’t exist yet is still a single-cup brewer with a “load it, push a button, and come back 3-4 minutes later for a finished cup of coffee” workflow that has a small enough footprint to have 4 or more on bar, going at the same time, costs under $1000USD each, and makes perfect coffee. I have some ideas about exactly such a machine, but until then, there’s a lot to improve about pourover gear.

Who is the December Brewer for?

If the December Dripper is successful, it’ll be because both coffee professionals and average coffee lovers at home find that it does make better coffee easier. That’s the goal. Pretty much the only goal.

Thank you Nick.