Matcha is a finely ground high quality green tea that is not the same as green tea powder. Matcha is made from shade-grown tea leaves also used to make gyokuro. The preparation of matcha starts several weeks before harvest up to 20 days, when the tea bushes are covered to prevent direct sunlight. This slows down growth, turns the leaves a darker shade of green and causes the production of amino acids. After harvesting, if the leaves are rolled out before drying as usual, the result will be gyokuro tea. However, if the leaves are laid out flat to dry, they will crumble somewhat and become known as tencha. Tencha can then be de-veined, de-stemmed, and stone ground to the fine, bright green, talc-like powder known as matcha.