Ratio Four Materials Breakdown

Curious to learn about our approach to plastics and how we pick materials for our machines? Please click here!

Water Tank — constructed of Eastman Tritan TX2001, a high-quality, shatter-resistant, BPA-free polymer plastic. No hot water contact.
- Click here for detailed information about the water tanks we use!
Water Lines — FDA-approved silicone. Hot water contact.
Shower Head — 304 stainless steel. Hot water contact.
Heating Element — crafted from the same aluminum as the Ratio Six and Ratio Eight's heater, in a more compact size. Hot water contact.
Brew Basket — constructed from a BPA-free polymer plastic. Hot water/coffee contact when in use.
- Looking to minimize plastic and hot water contact as much as possible with the Ratio Four? You have the freedom to swap out the Ratio Four's filter basket for a pour-over dripper constructed of a material of your choice! We recommend the Hario v60 in Size 01 or 02, which is available in ceramic and glass.
Glass Carafe and Heat Lid — hand-blown borosilicate glass; carafe heat lid features a thin silicone seal which helps it secure in place and retain the temperature of your coffee. Hot water/coffee contact.
Internal structure, water tank dock, and water line flexible cover — Metal. No hot water contact.

Curious about what materials are used in the youngest sibling of the Ratio family? Here's a closer look at how we thoughtfully selected each component for performance, safety, and longevity.