It’s peak Christmas season and workers across the world are pulling all-nighters to make sure gifts get to their intended destinations before the big day. At Cinco Jotas, a 142-year-old Iberian ham company in Jabugo, Spain, ham sniffers are pulling double duty. These experts are better known as caladores, the Wall Street Journal explains, named after the “cala” or probe they use to poke pork loins and give them “evaluative whiffs.” As a way of testing the ham’s curing process, the caladores puncture four specific areas in rapid succession—the hock, next to the hip bone, and twice around a joint of the hip and femur. After they probe, they immediately repair the puncture marks by smudging the perforations with fat from the meat. Experienced calador Manuel Vega Domínguez usually works alone, but during peak Christmas season he works alongside a team of six full-time sniffers, whiffing 800 loins a day. So, if you find yourself savoring a fatty, paper-thin slice of Cinco Jotas’ iberian ham at Christmas, think of Domínguez, who told the WSJ that during this time of year, he is strained “at the limit of human possibility.” —Tina Vasquez