Extraction lab
See the cup before you pour it
Every other coffee site hands you a recipe. We hand you the model behind it. Drag the dials and watch the real physics of extraction move in real time: how fast the solubles leave the grounds, where the cup lands on the brewing control chart, and how the flavor bends from sour to sweet to bitter. It is a model, not a refractometer, and it is honest about that. It is also the fastest way we know to teach the why behind a great cup.
The bench
Model v1 . 8 lotsSlow Roost Cold Brew
Sweet, balanced, and clear. The cup we are aiming for.
Control chart
Gold CupStrength up, extraction across. Land the dot in the Gold Cup box.
Extraction curve
How fast the solubles leave the grounds. Stop too early and it is sour, too late and it turns bitter.
Flavor radar
The cup your dial-in produces, bending around how we roast it.
Flavor genome
Every coffee placed by the catalog's own principal components. Watch this brew move.
The math behind the cup
The same equations the bench runs, with this brew's numbers underneath. A model, not a measurement: it is calibrated to our own reference pour, the way we cup it.
What fraction of the dry grounds dissolved into the cup. The SCA sweet spot is 18 to 22 percent.
Solubles leave the grounds fast at first, then level off toward a ceiling. k is the rate.
Hotter water (Arrhenius) and finer grinds (more surface area, as one over radius squared) both speed extraction up.
The Crow's full read
A roaster's analysis of your exact dial-in, and what to change.
Ask the Crow
grounded in your dial-inAsk the Crow
Coffee conciergeTell me how you take your coffee and I will point you at the right bag. Bright and fruity, smooth and chocolatey, bold and dark, something for lattes, or just say surprise me.