Ratio Basket Paper Filters

These filters are specifically engineered for the Ratio Four Coffee Maker. While they are a standard basket shape, they are optimized for the flow rate and dimensions of the Ratio Four, so we recommend using them only with that machine to ensure the best extraction.

Laboratory-grade paper is manufactured to a higher standard of purity and consistency than standard grocery store filters. This ensures there is no papery taste imparted into your brew and that the water flows through at a precise, uniform rate, which is critical for balanced extraction.

Yes. Because these filters are made from 100% virgin wood pulp without synthetic additives or bleaching agents, they are fully compostable along with your used coffee grounds.

While not strictly necessary due to the high quality of the paper, a quick rinse with hot water before adding your coffee grounds is a good habit. It warms your brewing basket and ensures the filter is fully seated against the walls of the basket.

These filters feature a 3.25-inch flat bottom and a 5.5-inch top width. While they fit the '8-12 cup' category, they are specifically tailored to the Ratio Four's basket geometry to prevent collapsing or bypassing during the brew cycle.