Intro To Pourover Brewers
Coffee is probably the most complicatedly uncomplicated thing we consume: Despite the fact that the drink itself only has two ingredients (coffee and water), there is a mind-boggling array of ways to combine those ingredients in order to get different—and special—results.
While the range of existing coffee-brewing devices runs along a very broad spectrum, from 24-hour cold brewers to 30-second espresso makers and everything in between, there’s one category of device that might be the most baffling in its sheer diversity: the manual coffee dripper.
Drip brewers are classified by their capacity to hold ground coffee stationary while the brewing water flows in and, simultaneously, finished brewed coffee flows out. They rely on the force of gravity—as opposed to pressure, as in espresso—as well as the interaction between contact time and total brew time. (For all you real coffee nerds: Contact time is defined as the duration that a certain amount of water is directly interacting with a certain amount of the coffee, while total brew time counts the length of the entire preparation.)
Some of the most recognizable names in coffee are drippers: Chemex, Melitta, Kalita, Origami, V60—even our electric friend Mr. Coffee. While these different brands share the flow in/flow out brewing that unite them as a category, they each have specific features that are designed to make them distinct—or distinctly complicated, depending on your point of view.
BASE
One of the primary differences among coffee-dripper devices is the shape of the bottom: This element has a big impact not only on the finished product, but also on your brewing technique.
The most classic dripper base shape is a cone: Think of the classic Melitta brewers that form a sort of triangular seal at the bottom, requiring those famous No. 2 or No. 4 filters.
Chemex and V60 brewers also create a cone-shaped brewing surface, with the ends of their filters peeking through the bottom. When you picture the coffee grounds sitting in the filters of these devices, you can imagine them having an upside-down pyramid shape.
Meanwhile, flat-bottom brewers like the Kalita Wave and most electric drippers, are designed to keep the filter level at its base, and are always closed on the bottom (as opposed to the open style of a Chemex or V60). When you imagine the coffee grounds in these brewers, you might picture them laying in more of a rhombus-like shape: Still tapered toward the bottom, but not quite as dramatically.
The difference is really in the brewing technique itself—which is to say, how you do your brew.
Flat-bottomed drippers are designed to restrict the flow of water through the base enough to create a kind of reservoir of brewing water on top of the bed of grounds, which creates an even flow through the coffee while also absorbing any agitation created by the brewing. For many flat-bottom brewers, the instructions will say to pour the water in concentric circles all the way around the filter’s circumference.
Conical brewer bottoms are designed slightly differently: Most will recommend pouring the brew water in slowly or continuously, in tighter circles and toward the center of the grounds bed. As the water flows through the filter in pursuit of that cone bottom, it is drawn toward the walls of the brewer, creating an even extraction by moving from the center outward.
Both designs have their merits (and their devoted fans), and each type of dripper will come with its own recommended brew guides—and most will also encourage you to buy disposable versions their proprietary filter. (Ebb filters are specially designed to match the specifications for the most popular drip brewers, though, so you don't have to worry about that.)
WALLS
Another consideration about the design of your brewer is whether the walls are flat or ridged. Imagine the smooth, uninterrupted glass walls of a Chemex, compared with the ridges inside a Bonmac or Melitta brewer. Raised ridges on the inside of a drip brewer will keep the filter slightly elevated in places, which allows some of the brewing water to by-pass the coffee bed. On the other hand, perfectly flat brewing surfaces will create a tighter seal between the grounds in the filter and the brewing water being poured through them, capturing the water inside the coffee bed and encouraging it to extract more aggressively.
One of the primary ways this impacts your brew is by dictating the contact time: Brew water may have a longer contact time in a flat-sided dripper, which can mean a higher extraction. It also is part of the reason certain brewers will come with instructions about how to pour your brewing water: Understanding the by-pass (or the lack of it) will be a key to maintaining a perfect extraction.
FLOW
How the dripper allows brewed coffee to flow out of the filter is the last significant piece to the puzzle, the main difference being the number of holes in a closed base (such as a Kalita or Melitta) and the circumference of an open base (for example, a V60 or Chemex).
The more holes and the larger their size, the faster the brewed coffee will be able to flow out of the filter, reducing the contact time: Here, again, is an interesting intersection between design elements, as an open-bottom brewer may have smooth walls (to reduce by-pass) and a greater density of grounds in the filter, while also allowing a steady stream of brewed coffee to flow through the coffee bed and into a holding vessel or mug.
Didn’t think that these simple-seeming brewers could be so complicated, huh? Don’t feel overwhelmed, though: Your coffee dripper will come with great instructions to get you started, and there’s a huge community of coffee nerds out there (including us!) who are more than happy to get overcaffeinated and troubleshoot with you.
Now quit reading, and start dripping!
ABOUT THE AUTHOR
Ever Meister is a coffee professional, journalist, and educator who has worked in the specialty coffee industry for 20 years, doing everything from making and serving espresso to selling green coffee to conducting training sessions and writing marketing strategies. Meister is also the author of New York City Coffee: A Caffeinated History (The History Press, 2017).