We believe quality design deserves the best materials.
The Ratio Eight and Six feature a cold water tank made of BPA-free co-polymer, and hot water lines made of handblown borosilicate glass.
You have your choice of brewing basket material. Some coffee professionals prefer plastic filters because they don’t absorb heat like glass and ceramic. They also lack the innate variation found in glass and ceramic, so each part is more consistent. Other people are trying to minimize plastic in their homes, or simply prefer the aesthetics of natural materials. Whatever you value, you’ll find some options in the Ratio lineup.
Here is our approach to plastics.
When we choose plastic for its performance, we always use BPA-free polymers from known reputable manufacturers like Eastman or 3M. The plastic we have incorporated into the Ratio Eight and Six is medical-grade quality, which exceeds food-grade standards. Made of polysulfone, this quality plastic is FDA-certified and a NSF-compliant material. Both the Ratio Eight and Six have a very small polysulfone part where the cold water enters the heating element, and this material was chosen due to its ability to form a water-tight seal without the risk of leaking as the metal expands and contracts during normal use.
The Ratio Six has plastic in the filter basket (where the coffee goes) and the thermal carafe lid. If you'd like to minimize your plastic exposure, we recommend using our glass carafe or the Ratio Eight ceramic dripper. Since we get this question a lot, yes the Eight ceramic dripper fits on top of the Six thermal carafe; it just doesn’t look very cohesive as they were not designed to work together.
Both the Ratio Eight and Sixes water reservoirs are made from Eastman Triton TX2001. Tritan has undergone thorough testing by third-party laboratories, guaranteeing its chemical safety. It is entirely devoid of bisphenol A (BPA), bisphenol S, and any other bisphenol compounds, as well as estrogenic and androgenic activity. Additionally, Tritan's shatter-resistant nature adds another layer of safety and durability to our reservoirs. With our machines, you can enjoy peace of mind knowing that your coffee experience is supported by the highest standards of safety and durability.
For further information, you can download and view Eastmans full SDS (Safety data sheet).