Butter is having a moment. No longer just a bit player in baking or a back-of-fridge standby, it’s taking center stage — whipped into sculptural boards, swirled into pastas, slathered generously on crusty bread. And yet, most of us still toss the same familiar yellow box into our grocery carts week after week. What actually makes a butter “better,” and which store-bought slabs are worth the splurge? To find out, we talked to chefs, cheesemongers and cookbook authors obsessed with butter — not just for the flavor, but for the science and soul behind it. We asked about butter for...