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 taste of the tea is fresh and clean with a slight nutty background, and a little like green tea without any bitterness or earthy flavor. I left the leaves in the bottom of the Pot, and now 30 minutes later I poured a second cup and it hasn't become bitter, still fresh and clean tasting only a bit cooler.