Green Tea Firing
Green tea is the least oxidized of the six tea types. Green teas are crafted with the application of heat in a step called firing. This heat denature the enzymes that cause tea leaves to change in color from green to yellow, to red and final brown in a natural process known as polyphenolic oxidation. Firing neutralizes these enzymes, halting oxidation and fixing the green color. This is what gives the category “green tea” its name. The degree of oxidation that is allowed before firing is the primary defining characteristic used to distinguish the six tea types.
In Japan, firing is most often conducted with steam heat, which rapidly blanches the tea leaves and fixes their bright green color. By comparison, in China and other origins, “dry heat” techniques such as pan-frying, tumble-roasting, oven-baking, and sun-curing are used.
Steamed green teas typically have a more vivid green color and umami-rich tasting notes such as “nori seaweed.”Green teas that are fired with one of the dry heat methods typically develop a more floral or nutty character. For instance, “toasted chestnut” is a common taste descriptor for pan-roasted Chinese green teas. After firing, the leaves are shaped to create a variety of green tea styles, each with its own character, flavor and aroma.
