Many believe that the wine Jesus drank was not an alcoholic beverage but simply the juice of grapes, or other fruits. Stewed fruit drinks like compote, sherbet or lemonade which are common drinks consumed with food in Middle East.
If you were to squash grapes and place the juice in a container at room temp you would soon have wine. Maybe a pretty terrible tasting wine, but it would have alcohol in it. Wild yeast are everywhere, especially on the skin of fruit. Without pasteurizing the juice and keeping it refrigerated in a container that had been sanitized the yeast would have gone to work. In Jesus' day they didn't know what yeast were. They didn't know what pasteurization was. They didn't have refrigeration. If any amount of grape juice was stored for any significant amount of time it would have either gone bad due to a bacterial infection or it would turn to wine as the yeast went to work. Yeast quickly edge out bacteria in surgery, slightly acidic liquids. Once the alcohol level increases the yeast have yet another defense against their mortal foe.
Beer and wine both probably occurred naturally or by accident. Back in the day it would have been difficult to NOT make grape juice into an alcoholic beverage. Any grape juice consumed would have had to have been consumed when it was very freshly produced and I imagine would have been quite the luxury. Wine with alcohol would by far be the predominate drink, would have been easy to preserve, easy to store, easy to transport. It may have been just a few percent alcohol, but it most likely had alcohol in it to some extent.