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.
Yerba mate is most commonly prepared hot or moderately hot in the 'straight-up' fashion, or otherwise prepared with roasted yerba mate leaves (the preparation being called mate cocido, which is distinctive for its more robust, 'spicier' taste and aroma).