can you identify astringent flavor? A common place to get astringent is green banana peel, ,, a feeling of drying the mouth, a feeling where the smoothness is gone in the mouth, pomegranate has some astringent.
,,, astringent is said to be related to long chain tannin complexes which can be removed with a protein fining agent.
oxidized ethyl alcohol (acetaldehyde) is a burn in the back of the throat at high level and apple like aroma at low level.
… acetaldehyde can not be removed
flavors go through the mouth in waves, sweet is fast followed by acid, ,, bitter (tannic) and astringent take longer.
letting air on a wine will change it from a sweet alcohol to the acetaldehyde (oxidized ethyl alcohol) and may allow growth of vinegar producing Acetobacter. As a rule NEVER allow free access of oxygen to an alcohol solution.