How is it ground up? What tea is used for it? Also can I make my own at home by just sticking green tea in a blender or coffee grinder to grind it into a powder, or using a mortar and pestle?
Matcha tea is a fine, powdered green tea used in Japanese tea ceremony and to dye and flavour foods such as mochi and soba noodles, green tea ice cream and a variety of wagashi. Matcha is generally expensive compared to other forms of tea, although its price depends on its quality. It can be hard to find outside Japan, as can the implements traditionally used to prepare and consume it, but you can find it easily in any tea-specialized shop as well as the apparatus used to brew it.
Prior to serving, the matcha is often forced through a sieve in order to break up clumps. There are special sieves available for this purpose, which are usually stainless steel and combine a fine wire mesh sieve and a temporary storage container. A special wooden spatula is used to force the tea through the sieve, or a small, smooth stone may be placed on top of the sieve and the device shaken gently. If the sieved matcha is to be served at a Japanese tea ceremony, then it will be placed into a small tea caddy known as a chaki. Otherwise, it can be scooped directly from the sieve into a tea bowl. A small amount of matcha is placed into the bowl, traditionally using a bamboo scoop called a chashaku, and a modicum of hot (not boiling) water is added. The mixture is then whisked to a uniform consistency, traditionally using a special kind of whisk made of bamboo known as a chasen. There must be no lumps left in the liquid, and ideally no ground tea should remain on the sides of the bowl.
Usucha, or thin tea, is prepared with half a teaspoon of matcha and approximately 75 ml (2.5 oz) of hot water. Some drinkers (and schools of tea ceremony) prefer to whip the mixture to produce a light frothy “head,” while others prefer as little foam as possible. Schools also vary on the amount of water and matcha. Usucha creates a lighter and slightly more bitter tea. Koicha, or thick tea, requires significantly more matcha, as many as six teaspoons to 3/4 cup of water. Because the resulting mixture is significantly thicker, blending it requires a slower, stirring motion which does not produce foam. Koicha produces a sweeter tea, and is served almost exclusively as part of Japanese tea ceremonies. Special chasen designed for this purpose are often employed.