With Decaffeinated Tea taking caffeine out and keeping it proper can be tricky. For Brew Tea Co, rather than using the scarily-named dichloromethane solvent method, they prefer the carbon dioxide (CO2) decaffeination process. When compressed, CO2 behaves partly like a gas and partly like a liquid, rather usefully CO2 has the property of combining selectively with caffeine in this state, the caffeine is then removed from the carbon dioxide through charcoal filtering. Easy to do and creates a tasty caffeine free tea.