Ordering a “proffee” at your local café may still elicit quizzical looks, but protein coffee is gaining momentum. In March, Tim Hortons launched a new range of high-protein dairy beverages, including a latte containing 20 grams of the nutrient in a medium-sized cup. Now, Starbucks is entering the fray. The coffee giant announced at a leadership conference in Las Vegas on June 10 that it’s testing protein coffee at select locations in the United States.