Ifu y'ikirahure cya vino (bitartarate ya potasiyumu, KC₄H₅O₆) — ifu nziza y'umweru iva mu bikorwa by'ivino, igwa nk'ibikristali imbere mu bitebo mu gihe cyo kwiheza. Mu gusiga amabara karemano ifasha igifata ibara cya alum: ifasha alum gukwira kimwe mu buzi, ikagumisha ubwoya bworoshye, kandi ikagaragaza amabara ya nyuma neza yongereye ubukarara buke mu mazi. Mu gukora imigati ni igitera kuzamuka kandi ihamya amagi yakubiswe.