How does supercritical CO2 extract caffeine without caffeine also being supercritical?

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IIUC, supercritical CO2 is as dense as a liquid yet also able to diffuse like a gas to the point where it can diffuse through a coffee bean the same way coffee diffuses through a coffee filter. How though does the caffeine structure get extracted from the bean without ripping the bean apart if the caffeine also isn’t in a supercritical state?

I’m imagining this to something like trying to extract the drivers seat of a car without opening the door. The door would get ripped off if I tied a rope to the seat and drove off.

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Anonymous 0 Comments

Supercritical CO2 is a solvent. Imagine you have a sponge that you have soaked in salt water and then let dry so all the little holes in the sponge are full of salt crystals. Then you dip the salty sponge in fresh water. The salt would dissolve and travel out of the sponge.

At an atomic level a coffee bean is like a sponge with a whole lot of tiny holes. Also caffeine is pretty small so it is like trying to extract the change from the ashtray of a car and the window is open.