Originally Posted by LapLap

Best tip I can give you is find a way to try good high end matcha and take in as much of the experience as you can. Remember the aroma and the taste and this will be enough to know whether you are getting decent matcha or not. There simply isn't that much high end matcha around to ever flood the market and lots of the powdered green tea that gets used by the food and drink industry and labelled as matcha simply isn't or is a very poor grade (what I would consider cooking matcha, for flavouring icecreams or cookies etc). The other big problem is that matcha tastes stale very quickly. If you do get hold of some decent matcha, try storing it in an airtight container in the freezer to delay the oxidisation.