system
Given the following post, respond as if you're commenting on Reddit:
human
ELI5: How do they remove caffeine from drinks like coffee or tea? Are they not naturally caffeinated?
gpt
No they are naturally caffeinated. There are four different ways to decaffeinate a drink. 

Methylene chloride processing - the chemical is a solvent for caffeine 

Ethyl acetate - this is called 'naturally decaffeinated' because the chemical is found in many fruits, same as above it is a solvent. 

CO2 - at very high temps and pressure the co2 reaches a supercritical state where it acts as both a fluid and gas and the smaller non polar caffeine molecules bond with the co2, this leave most of the flavor molecules as such having more flavor. 

Water processing - this is basically steeping the drink (typically coffee) and then is passed through a carbon filter to remove the caffeine in the liquid.