Maesil-ju (매실주; 梅實酒), also called plum wine, plum liquor, or plum liqueur, is an alcoholic drink infused with maesil (plums).
Maesil-ju is made with maesil (매실; 梅實; “plums”), preferably ripe hwangmae (황매; 黃梅; “yellow plums”), which are yellowish in color, fragrant and firm. Unripe cheongmae (청매; 靑梅; “green plums”)—firmer and less fragrant—can also be used. Bruised or over-ripened plums may make the wine cloudy.
Damaged fruits should be avoided, as direct contact of plum seeds with alcohol may produce a small amount of prussic acid, due to the amygdalin in plum seeds. However, toxicity vanishes after a year of maturation. Ripe plums have much lower amygdalin content.