When Edmund Hillary and Tenzing Norgay summited Everest in May 1953, they weren’t fueled by carbohydrate cocktails and fancy gels or advised by a trained sports nutritionist. Instead, they were powered by intuition and an English candy experiment gone wrong.
In 1869, English confectioner Joseph Wiper was trying to make peppermint creams. At one point, he took his eyes off the sugar he was boiling, and it began to granulate and turn an odd opaque color. Wiper let the mush cool and ended up happy with the result. He began selling the “mint cakes” from his hometown of Kendal, on the edge of the British Lake District.
The Kendal Mint Cake is not, in fact, a cake at all. Fudge-like in texture on the outside with a peppermint patty–style filling, it’s more like an enlarged York candy. It’s made from just sugar, water, syrup, and peppermint oil—not exactly a nutritional powerhouse. But it unintentionally became a favorite with local hill walkers and climbers almost as soon as it was put to market in the late 1800s. That’s because when you’re burning straight through calories—as many as 20,000 of them on an Everest summit day—pure energy is exactly what your body wants. Just one of these bars contains about 379 calories of quick-digesting glucose, so they soon became an easy, tasty way to meet those energy needs.
Seven days before Hillary’s group set off for Nepal, one of the mountaineers saw an advertisement for the mint cake in a climbing magazine. He wrote to the confectioner with an urgent request for 38 pounds of the candy—the amount one porter could transport up the mountain by himself. Sweets were still strictly rationed after World War II, so the confectioner and his staff had to pool their ration coupons together to fill the order.