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Coffee decaffeination processes
Kurt Zosel · Max-Planck-Institut für Kohlenforschung · 1970 · mpg.de
The institutional record of supercritical CO₂ decaffeination, invented by Kurt Zosel and patented in 1970. Establishes the mechanism and the physical conditions the process depends on.
How much weight this carries
Well established. Safe to rely on as stated.
What it says
- CO₂ becomes supercritical above 31.1 °C and 73.8 bar — Commercial decaffeination typically runs at 200–300 bar.
- Supercritical CO₂ diffuses like a gas but dissolves caffeine like a liquid
- The method is highly selective for caffeine over larger flavour precursors, sugars and lipids
- Patented in 1970 by Kurt Zosel
What it does not say
- Not all commercial "CO₂ decaf" is supercritical. CR3's process is documented as subcritical liquid CO₂ at around 23 °C and 70–80 bar — a real distinction if you are naming the process on a bag.
Recorded because the errors in this subject all point one way: toward claims more confident and more flattering to decaf than the evidence supports.
Cited on
Related sources
- Mountain Water Process Industry source · Descamex
- Swiss Water — decaffeination process and caffeine content Industry source · Swiss Water Decaffeinated Coffee Inc.
- The effect of decaffeination on coffee's roasting and grinding performance Trade press · Independent research write-up