Definition and Composition:
Sour wine, often referred to as vinegar in biblical texts, is a fermented beverage made from wine that has turned acidic. It was a common drink in ancient times, particularly among the lower classes and soldiers, due to its affordability and refreshing qualities. The sour wine mentioned in the Bible is likely a diluted form of vinegar, which was less expensive than regular wine.

Biblical References:
Sour wine is mentioned in several key passages in the Bible, often in contexts that highlight its use as a common, everyday drink. One of the most notable references is found in the accounts of the crucifixion of Jesus Christ.

1. Crucifixion of Jesus:
During the crucifixion, Jesus was offered sour wine to drink. This event is recorded in all four Gospels, emphasizing its significance. In the Gospel of John, it is written: "A jar of sour wine was sitting there. So they soaked a sponge in the wine, put it on a stalk of hyssop, and lifted it to His mouth" (John 19:29). This act fulfilled the prophecy found in Psalm 69:21, which states, "They gave me poison for food, and for my thirst they gave me vinegar to drink."

2. Psalm 69:21:
The psalmist's lament in Psalm 69 is often seen as a messianic prophecy, pointing to the suffering of Christ. The offering of sour wine to Jesus is seen as a direct fulfillment of this prophecy, underscoring the connection between the Old Testament and the New Testament.

3. Proverbs 25:20:
Sour wine is also mentioned metaphorically in Proverbs: "Like one who takes away a garment on a cold day, or vinegar poured on soda, is one who sings songs to a heavy heart" (Proverbs 25:20). Here, the reaction of vinegar on soda (likely natron, a type of alkali) is used to illustrate the inappropriate nature of certain actions, highlighting the disruptive and unsettling effect.

Cultural and Historical Context:
In the ancient Near East, sour wine was a staple for many, especially soldiers and laborers. It was often mixed with water to make it more palatable and to provide a safe alternative to potentially contaminated water sources. The Roman soldiers stationed in Judea would have been familiar with this drink, which explains its presence at the crucifixion site.

Theological Significance:
The offering of sour wine to Jesus during His crucifixion holds deep theological significance. It symbolizes the fulfillment of Old Testament prophecy and highlights the suffering and humility of Christ. The act of giving sour wine to Jesus can be seen as a final gesture of mockery by the soldiers, yet it also serves as a poignant reminder of His willingness to endure suffering for the sake of humanity.

Conclusion:
Sour wine, while a simple and common beverage in biblical times, carries profound symbolic weight within the scriptural narrative. Its presence at the crucifixion of Jesus serves as a testament to the fulfillment of prophecy and the depth of Christ's sacrificial love.