I always feel a little awkward merely re-wording information I gathered from other blogs and sites if I don't have anything new or original to add; however, since the following posts this week will cover my first ventures into the world of matcha, I think it is important to at least cover the basics.
Matcha (抹茶) comes from tencha (展茶), tea that is grown in the shade for three weeks prior to harvest. Tencha is then destemmed and deveined and ground into a fine powder, matcha, which is what is used for cha no yu. It is important to remember that not all powdered green tea is matcha.
There are two types of matcha, usucha and koicha.
Usucha (thin tea) is more astringent and not as sweet as koicha, so less is used, approximately two scoops using a chashoku.
Koicha (thick tea) is a higher quality matcha, sweeter, allowing more to be used, approximately four scoops.
How to Brew Matcha
For best results you need a minimum of three things, a chawan (tea bowl), chasen (tea whisk), and a chashoku (tea scoop).
For usucha, start with two scoops and 3-4 oz of water at 175 F, then whisk briskly from side to side. You do not want to use a circular motion. The video should adequately demonstrate what I'm talking about.
I am unclear on the brewing instructions for koicha; I've read different things from different sources, so I'll experiment more before posting the instructions later this week.