The ingredients and manufacturers were unknown and watered-down methyl alcohol, toxic to humans, was sold at worst and all the bad products that made people sick, were commonly called "kasutori" and therefore a common image was established that kasutori were bad distilled liquors.
原料・出所がまったく不明、甚だしい例では人体に有毒なメチルアルコールを水で薄めたものまで売られる始末で、これら悪酔い確実な代物が俗に「カストリ」と総称されたため、一般にも「カストリ＝粗悪な蒸留酒」というイメージが定着した。