Pour-Over Lab: swap the dripper, change the pour, how much does the same coffee change?
Drag four sliders (grind, water temperature, brew ratio, pour rate), then switch between five drippers and five pour methods (single pour, two-stage, three-stage, pulse, the 4:6 method) and watch brew time, extraction and strength move. A simplified teaching model for finding the right direction.
When a pour-over tastes too sour or too bitter, people usually reach for two numbers. Extraction is how much of the coffee’s weight the water carried away. Strength is how much ended up dissolved in the cup. The brewing control chart most people quote marks 18–22% extraction and 1.15–1.35% strength as the “ideal” box in the middle.
The gear below moves with your settings. Grind finer and the particles in the dripper shrink while the water drains more slowly. Pour faster and the stream from the kettle thickens and the water level in the dripper rises sooner. Press ”▶ Brew” to watch a whole cup in fifteen seconds.
The two rows of buttons are the point of this one. There are five drippers: the V60 cone with one large hole, the ceramic KADOU starburst cone with 32 long and short ribs inside, the flat-bottomed Kalita with three small holes, the Melitta wedge with small holes, and the Clever dripper, which steeps first and then lets the coffee out. There are five pour methods: a single pour after the bloom, two-stage, three-stage, pulse pouring in small frequent amounts, and Tetsu Kasuya’s 4:6 method, which won him the 2016 World Brewers Cup. The “Compare” table runs every option at your current settings and lines them up.
What surprised me most while playing with it: changing the pour method mostly changes how high the water sits in the dripper and how long the brew takes. Extraction moves by only a point or two. The thing that actually pushes a cup from sour to bitter is still the grind.
The limits, up front: this is a teaching model built from a few simplified formulas. It shows which way to turn a knob, not what your next cup will taste like. A real brew also depends on the beans, the roast, the filter paper and your hands. Take water slipping past the coffee bed down the side of the dripper: even people who study pour-over closely say they can’t measure how much of it happens, so the model’s number there is only illustrative.
The one thing to take with you
Find the strongest knob first, then fine-tune the rest. Before switching to a new method, ask whether it changes the process or the result. Many methods that look very different end up closer than you’d expect.
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