The December Dripper, released in 2019 by Eightounce Coffee's in-house brand, is the dripper that made variable flow mainstream. A rotating collar at the base lets the brewer choose between three flow rates — fast, medium, slow — effectively turning one dripper into three. The body is a 60-degree cone similar to a V60, and the flow settings feel different enough that each one suits a different coffee style.
The fast setting behaves like a more open V60 and suits high-extraction light roasts and competition-style recipes. The medium setting lands close to a standard V60 and works as a daily driver. The slow setting slows drawdown to Kalita Wave territory and produces the sweeter, body-forward cups usually associated with flat-bed brewers. All three use standard V60 02 paper filters.
A starting recipe on the medium setting: 15 g of coffee to 250 g of water (1:16), medium grind, water at 94 °C, four pours in 3:00 to 3:45. The real point of the December is experimentation: once you have a recipe that works on medium, moving the dial to fast or slow teaches more about flow's effect on extraction than any book chapter could.