The just-released Riverbelle is one of well over 100 new apple varieties to hit markets around the world in the past six years. Courtesy of Honeybear Brands hide caption toggle caption Courtesy of Honeybear Brands The Salt Sweet. Tart. Crunchy: How To Engineer A Better Apple October 9, 2013 Over the past six years, an estimated 130 new apple varieties have hit markets around the globe. And behind every crisp, tasty bite, there's a world of plant breeding — and decades of painful trial and error.