NAIROBI—Bill Gates announced a global toilet tour Tuesday, confirming he will personally taste-test every sanitation unit his foundation deploys. He arrived with a carry-on of tasting glasses and laminated scorecards. The program covers 3,000 units in 41 countries by December. Each toilet will receive a Michelin-style rating for mouthfeel, finish, and aroma integrity. “We believe in measurable outcomes,” Gates said, rinsing a tulip glass like a sommelier in a lab coat. Engineers in Kisumu watched him swirl a sample under fluorescent lights. “Hints of limestone, admirable mineral backbone,” he murmured, scratching two stars onto a waterproof clipboard. A field officer offered crackers as palate cleansers. In Mumbai, Gates revised scoring after a composting model showed “cheeky effervescence” at room temperature. He praised a Dakar prototype for “confident legs and a responsible afterglow.” Local officials applauded. One mayor asked if gold-plated flush handles improve terroir. “Only if ventilated,” Gates replied, misting his mouth with pH-neutral spritzer. By São Paulo, Gates introduced a Reserve list for exceptional lavatories. He debuted a velvet rope, a spittoon, and a ceremonial plunge-thru for three-star winners. Reporters asked about safety. Gates nodded, then requested the 2019 pilot’s “vintage” for comparison. “We’re chasing a crisp, democratic sip,” he said, holding up a glass. “No notes.”