Think there’s no difference between frozen yogurts? Think again. Tiffany Hauser and Dustin Naugle, co-owners of salad-focused Green + the Grain food truck, know better, because they serve a light, creamy, snowy-white and unapologetically tangy soft-serve frozen yogurt. It’s an organic, new-to-Minnesota product, and its tart, clean bite is a welcome change from grainy, insipidly sweet fro-yos. Sure, the topping selection isn’t as vast as what a fro-yo fan might encounter at a chain outlet (it pretty much falls along the lines of fresh berries and toasted coconut), but who needs distractions when the frozen stuff is this refreshing? Even better: Naugle and Hauser are following in the tire tracks of many of their food-truck brethren and opening a brick-and-mortar location in early summer, on the skyway level of LaSalle Plaza in downtown Minneapolis. @GreenNtheGrain