If you’ve ever visited a Blue Bottle Coffee shop, you’ll notice that there are no giant urns of hot coffee behind the counter. That's by design. “Everything we make is made to order,” explains James Freeman, the company’s founder and chief product officer. This ensures that each drink is as fresh as possible. “So this act of making coffee,” using the pour-over brewing method rather than the big-batch drip coffee method you'll find at many cafes, “is a huge part of our business,” he says. “If we can make that act 20 percent, 10 percent, 4 percent more delicious, then it’s ultimately going to be worth the fuss and the bother.”
That commitment to making the best cup of coffee possible is exactly why Freeman and Blue Bottle hired engineers to rethink and redesign the device they use to make their pour-over coffee. After a year of research, about 70 prototypes, and countless cups of coffee, the team of four engineers came up with the Blue Bottle Coffee Dripper.
This device basically looks and works like most other pour-over brewers. But every millimeter of Blue Bottle’s pour-over coffee dripper is considered, designed, and tested to make the best cup of coffee every single time with as little effort as possible—and to look good while doing it.
The result of all this hard work is a pour-over brewer that’s nice to look at, simple to use, and makes a good cup of coffee every single time.
The design started with the size of the nozzle. “If it’s too small then it’s a slower extraction, and sometimes that’s problematic,” Freeman says. “If it’s too big, then too much art and technique is expected with the pour.” And the difference in sizes was tiny, down to tenths of millimeters. The optimal diameter for this dripper was exactly 4.45 millimeters.
After the size of the nozzle was locked down, the engineers started looking at the interior of the dripper, specifically the ridges. Though Freeman initially thought that higher ridges would help hot water flow through the device more easily, the engineers explained that “If you make the ribs slightly, slightly shorter than the height of one droplet of water, then through the principle of capillarity,” which is what helps water rise up from a plant’s roots to its leaves, “the water will be pulled through very evenly.”
Once the optimal height was determined, the ridges had to be place inside the dripper. “There’s an optimal number of ridges per a given surface area, and if we had too many then they were going to clog up, and we wouldn’t be able to get the same free-flow of hot water,” Freeman says. “And if we had too few, there would be these peaks and valleys.” Eventually, the team settled settled on 40 evenly spaced, straight ridges that run right toward the nozzle.
The reason for making a brewer with a flat bottom rather than a more conical-shaped device was simple. “We have less turbulence if we have a flat bottom and a more uninterrupted cylinder of water on top of it,” Freeman says. To limit turbulence means to make sure the flow of water is as smooth as possible, meaning the coffee extracts at an even, measured rate.
Thin Porcelain Walls
Part of the reason to make the dripper out of porcelain instead of plastic was an environmental one. “I would rather not be in the business of putting more plastic in the world,” Freeman says. But the thinner porcelain walls are also optimized for heat retention. What that means, in layman’s terms, is that it will lose less heat than a more massive pour-over brewer as you brew. It’s also a “beautiful, delicate shape and form, which I find very pleasing,” Freeman says. These brewers are made in Arita, Japan, “a region that has a history of making ceramics, and they’re capable of doing things at a very high degree of precision.”
According to Freeman, you want to forget the handle is there. “It’s just a handle. It’s unobtrusive,” he says. “To make it perfectly proportioned, you might want to have it smaller. But we tested it with a lot of different people picking it up, men and women and kids. And that shape of the handle made it the most useful, the less inclined to drop.” The slightly-too-large look also adds to the charm of the device. As Freeman described it, it's like a "cute little kid with ears that are slightly too big.”
Freeman’s goal for the dripper was to look “elegant, but not superficially elegant,” and the team worked to perfect the edge where the dripper contacts the carafe, as well as the midsection of the device in order to achieve those sleek aesthetics for which Blue Bottle is known. “There’s a radius curve,” he explains. “It’s not just cool because it’s an Apple Store thing, but it’s cool because you really can’t see an edge to it. So it’s easier to clean, and it has this more timeless quality.”