Bava Batra 96 - Wine that Sours | Talmud Illuminated

Rav Yehudah said, "The souring wine sold in shops still retains the blessing over wine, that is, "Who created the fruit of the vine." Rav Zevid said, "Why should I say a blessing over wine that has soured? Rather, the blessing is "Who created everything by His word." Rav Yehudah agrees that wine sold on the corners, which the thirsty, indiscriminate public consumes in haste, is not wine at all.

If one bought a barrel of wine and it spoiled within three days, then Rav says that it was beginning to spoil at the time of the sale, and therefore, it is a mistaken purchase, which can be returned. Shmuel says that "it is on his shoulders." This means it was either spoiled while being carried or the spoilage was due to the owner's sins.

Art: Man with a glass of wine by Frans van Mieris