Doubling the dose and water does not double the brew — bed depth changes the physics.
What stays the same
The ratio. 1:16 is 1:16 whether it is 15 g or 30 g.
Temperature.
What changes
Time gets longer, disproportionately. A deeper bed means more resistance, so the water passes more slowly. A 30 g V60 can take 4 minutes where a 15 g takes 2:45.
Extraction rises for the same reason — longer contact.
The adjustment
Grind one or two steps coarser when you double, to bring the time back down.
Otherwise the larger brew will be over-extracted relative to the small one, at the same setting.
Use the right size brewer
A V60-01 cannot take 30 g. A V60-02 handles 15 to 30 g comfortably. A Chemex 6-cup wants 30 to 45 g.
Too much coffee in a small cone overflows and channels. Too little in a big one gives a shallow bed that channels the other way.
Pouring larger brews
More pours, not one bigger one. Four pours of 100 g rather than two of 200 g keeps the bed from flooding and the level manageable.
Above about 40 g
Switch method. A Chemex, a batch brewer or a large French press is designed for volume, and a V60 is not.
The easy option
For two or more, a full-immersion brewer or a filter machine is more consistent than scaling a pour-over. Bed depth stops being your problem.
Last reviewed 8 August 2026