The flavour of Matcha is determined mainly by its amino acids. The highest matcha grades are intensely sweet and have a deep and rich flavour, much more than lower classes that will be harvested later in the tea harvesting season. There are three primary matcha grades.
The ceremonial grade is the highest of matcha grades. This is the matcha that is used during tea ceremonies and in Buddhist temple tea activities. It is ground on a granite stone mill and goes for a price of 100-140 $ USD for 100 grams. Ceremonial matcha is known to possess tones of umami flavour.
Premium grade is produced from leaves from the top of the tea bush. The top leaves produce higher quality and more desirable tea and premium grade matcha reflects this. Premium grade sells for 50-80% USD for 100 grams of matcha. Premium is noted to have a fresh flavour.
Food/culinary grade is the lowest grade and also the cheapest of matcha grades. Culinary matcha sells for 15-40$ USD for 100 grams. The culinary class usually has a bitter flavour because it uses tea leaves from lower on the bush.
Some variables help to determine the grade of matcha. The placement of the leaves on the bush is a significant factor. High leaves produce sweeter tea, while lower leaves, conversely produce more bitter brew. The more top quality leaves are also softer and more comfortable to grind while lower leaves are sturdier and make for a sandy grind. As for the drying process, the leaves are dried in the shade, and increasingly indoors. Being drained out of direct sunlight contributes to the tea having a brilliant green colour. Matcha is also stone-ground, if not ground by a grinding stone, it can be burnt and suffer from reduced quality as a result. Matcha is incredibly sensitive to oxidation, and if exposed to too much oxygen can turn brown and take on an unpleasant hay-like smell and less palatable taste