Martin Riese, who you might remember from this episode of Most Expensivest Sh*t serving 2 Chainz and Diplo the world’s most expensive water, is back. Riese is one of the few water sommeliers in the world, who makes a profession out of tasting, analyzing, judging and trying different types of bottled waters hailing from all corners of the Earth. While this may seem crazy, different flavors, compositions and varieties of water are indeed celebrated. French retailer colette even has a Water Bar serving all types of waters. Check out the video above to learn what Riese does, and why he thinks it’s important.