puresteel.

/About

About Puresteel

01Founder's note

Creating Puresteel was about solving a problem that hits close to home and helping humans thrive.

When I went looking for a plastic-free coffee maker, I came up empty. Every “stainless steel” option I found still had hidden plastic valves, tubes, and reservoirs leaching chemicals into the brew.

I realized that if I wanted safe, clean coffee without microplastics, I'd have to build the machine myself. So I did. Puresteel is the result.

JC Foster / Founder, Austin, TX / @jcfosterx
Puresteel coffee maker, brushed stainless steel body with a glass carafe, three-quarter view
Fig. 1Three-quarter view

02Mission

Building contaminant-free appliances that help humans thrive.

The coffee maker is our first product. Anything we make after it follows the same rule: no plastic where it touches water or food.

Built from steel and glass.

No plastic in the water path. The tank, valves, showerhead, pipe, body and filter are 304 stainless steel. The carafe is borosilicate glass. Independent lab testing for microplastics is underway. The machine will be tested and certified by a nationally recognized lab.

03Results

Averages from Puresteel testing, compared with the Specialty Coffee Association ideal ranges.

Puresteel coffee maker / Test resultsPuresteel testing
Average brewing temperatureR1
200°FAverage across Puresteel test brews. 
Total dissolved solids (strength)R2
1.31%Specialty Coffee Association ideal: 1.15–1.35%.Within range
Extraction yieldR3
20.3%Specialty Coffee Association ideal: 18–22%.Within range
Strength versus extractionThe Puresteel average, 20.3 percent extraction at 1.31 percent total dissolved solids, sits inside the Specialty Coffee Association ideal box of 18 to 22 percent extraction and 1.15 to 1.35 percent strength.1.001.101.201.301.401.501618202224SCA idealPuresteelaverageExtraction yield, %Total dissolved solids, %
Fig. 2Strength vs. extraction. Specialty Coffee Association ideal shown in blue.

Notes

  1. 1Values are averages from Puresteel testing.
  2. 2Ideal box from the Specialty Coffee Association brewing chart: strength 1.15–1.35% total dissolved solids, extraction 18–22%.

04Specs

Capacity
12 cups
60 oz glass carafe.
Control
One switch
Electromechanical. No app and no firmware.