First flush means this matcha is ground from the first leaves plucked during tea harvest. This selection is produced in Shibushi Dist., Kagoshima Pref., Japan. Matcha is made from young tea leaves, shaded for 2 - 3 weeks, then plucked, heated, dried, and ground into a powder. As one is consuming the actual leaf, as opposed to drinking the brew steeped from the leaf, caffeine intake is higher, and available nutrient count is also elevated.