noun
so (ancient Japanese condensed milk product)
Historical term for a dairy product made by repeatedly boiling down milk, similar to a thick condensed milk or milk curd, consumed in ancient Japan.
蘇は古代日本の貴族が食べていた乳製品だ。
So is a dairy product that the nobility of ancient Japan ate.
文献によると、蘇は牛乳を長時間煮詰めて作られた。
According to documents, so was made by boiling down milk for a long time.
The word 蘇 (そ) is of uncertain origin, possibly derived from the process of 'reviving' or 'condensing' milk, but the exact derivation is unclear.