High acidity/sourness comes from under-extracting, not over-extracting. Too high of a brew temp will bring out bitterness, not sourness.
To fix sourness, either use hotter water, finer grind size, or longer contact time with water.
High acidity/sourness comes from under-extracting, not over-extracting. Too high of a brew temp will bring out bitterness, not sourness.
To fix sourness, either use hotter water, finer grind size, or longer contact time with water.