Flavored beans are generally glazed in propylene glycol. The flavor of the beans will contaminate your grinder, brewer and brew pot so that sequential brewed cups taste like the previous flavored beans. Propylene glycol's safety is questionable; I know that it burns my throat when I try to drink flavored coffee. It's better to buy flavor syrups and flavor your coffee after it's brewed. Some grocery stores sell flavor syrup.