RS-16 Intense Extraction Glass Filter w/Cup Holder
The RS-16 is developed in Germany by Coffee Consulate and bears a few similarities to the Walkure-style brewers.
The RS-16 is a single serve glass cup, with small openings in the bottom. Glass, unlike metal, cloth and paper is inert and non-porous, it doesn’t react with other elements or trap certain elements. Compared to a cloth or even a metal filter, the openings in the bottom of the RS-16 are huge, which calls for rather coarse ground coffee. The coffee we used was ground to a coarseness similar to what you’d need for a French Press.
The coffee that you brew with the RS-16 is one of the most pure extractions you can create. Everything that dissolves out of the bean and into the water, ends up in your cup. Unlike brewing systems that use traditional filter media, you can’t really experiment with the coarseness of the grind to influence the taste of the coffee. You can however add more or less coffee and / or water, or play with the water temperature. If the coffee tastes too watery, add more coffee or less water. If the extract is too strong, use less coffee or more water. Grounds falling through the RS-16 and / or sediment in your cup means you are grinding the coffee too fine.
An Unfiltered Opinion
The RS-16 makes it possible to brew without altering the taste and quality of the coffee itself. It’s rather easy to clean as well, just water and soap will do it. Did I mention you don’t need a filter either? That means that it’s truly a one-time investment, you don’t have to keep buying paper filters.