Which method is used to extract the caffeine?

Vergnano does not state the method on the pack; the industry uses Swiss Water, CO2, ethyl acetate or DCM.

How is the caffeine removed from this decaf?

Caffè Vergnano does not state on the pack of the 1882 Decaffeinato Espresso which method was used to remove the caffeine, so we cannot say for certain for this particular coffee. If you want to know for sure, email our customer service and we will check with the supplier.

In the coffee world, caffeine is removed from the green bean in four ways:

Swiss Water: water and carbon filters only, no solvents.
CO2 method: liquid carbon dioxide that targets the caffeine specifically.
Ethyl acetate (EA): a natural solvent, also known as sugarcane decaf, that evaporates out of the bean again.
DCM: dichloromethane as the extraction agent, in which the green beans are soaked.

The decafs from our own Café du Jour brand are CO2 or Swiss Water decafs, so without chemical solvents.