Muscle twitching is caused by minor muscle contractions in the area, or uncontrollable twitching of a muscle group that is served by a single motor nerve fiber. Muscle twitches are minor and often go unnoticed. Some are common and normal. Others are signs of a nervous system disorder.
Yerba mate has a slight astringent bitter taste due to the high tannin content of the leaves. Researchers have found that leaves from younger plants possess more tannins than leaves from older, more mature trees.
The fresh leaves are a bit fuzzy, and not terribly pleasant to taste. They taste a lot like any leaves, but with a mild lemony scent. Lemon balm tea is delicious, and is particularly good iced.