What decaffeination method does Peet’s use? December 14, 2021 17:55 Updated We utilize the water process method for all our decaf ground, whole bean and K-cup® coffees. Related articles Does Peet’s use the Swiss Water process? How much caffeine is in Peet’s Decaf coffees? How does the water process work? Is your coffee grown with pesticides? Are Peet’s K-cups also decaffeinated using the water process method?