A barista can change your day. Be it with a simple smile or by remembering your favorite drink, they help get your morning started. But a barista like Mariah Patzner at Kopplin's coffee in St. Paul can change your life. For reals. One sip will make you a believer. She honed her craft in the hills of Eugene, Oregon, at a small roaster called Wandering Goat. There she went through a barista boot camp of sorts, spending days learning how to mete out 20 grams of espresso from a burr grinder, tap the grinds with 20 to 30 pounds of pressure, and perfect a ristretto pull by watching, smelling, and timing the water moving through a naked portafilter. If you have no idea what that means, don't worry. Patzner would just as soon talk about her other love, one more familiar to St. Paul natives: books. As for her own craft, one simple sip of espresso made with her care, attention, dexterity, and love will change the way you experience coffee. As a result, Mariah Patzner will change your life.