Ratio Basket Paper Filters

These filters are specifically engineered for the geometry of the Ratio Six and Eight S2 basket. While they might physically fit other flat-bottom brewers, we recommend using them only with the intended Ratio models to ensure the precise flow-through and extraction performance they were designed for.

The taller sides are a practical design feature that prevents coffee grounds from splashing over the edge during the bloom and brew cycle. This keeps your grounds contained within the filter, resulting in a cleaner cup without sediment in your carafe.

Yes, rinsing your paper filter with hot water before adding coffee is a best practice. It removes any residual paper taste and pre-heats your brew basket, ensuring your first cup is as clean and temperature-stable as possible.

Laboratory-grade paper is manufactured with higher consistency and purity standards than standard grocery store filters. This ensures a uniform flow rate through the filter, which prevents channeling and helps you achieve a more even, balanced extraction every time you brew.

Because these filters are designed for a specific basket shape, you may need to gently press the bottom of the filter into the corners of the basket to ensure it sits flush. Once the water starts flowing, the weight of the grounds will naturally settle the filter into place.