Bars lose 20% of their alcohol to overpours and “free” drinks for friends. That amounts to $50 billion per year in booze that mysteriously disappears, making life tough for every pub and restaurant. Nectar wants to solve that mystery with its ultrasound depth-sensing bottle caps that measure how much liquid is left in a bottle by measuring how long it takes a sonar pulse to bounce back. And now it’s bringing real-time pour tracking to beer with its gyroscopic taps. The result is that bar managers can determine who’s pouring too much or giving away drink, which promotions are working and when to reorder bottles without keeping too much stock on hand — and avoid wasting hours weighing or eyeballing the liquor level of their inventory.