While the Mishnah and Gemara are clear that wine should be drunk diluted, the opinion that wine was too strong to drink came from later commentators, writing hundreds of years later. In the Gemara itself, Rav Oshaya says that the reason to dilute wine is because a mitzvah must be done in the choicest manner. Indeed, the Gemara itself seems to allow that undiluted wines were drinkable – it was just not considered civilized behavior. A ben sorer umoreh, a rebellious son, is one who drinks wine — wine which is insufficiently diluted, as gluttons drink. In other words, undiluted wine was drinkable, but it was not the civilized thing to do.
A review of the history of civilizations reveals the origin of the preference for diluting wine: Greek culture. The first mention of diluted wine in Jewish texts is found in the apocrypha: about 124 BCE, “It is harmful to drink wine alone, or again, to drink water alone, while wine mixed with water is sweet and delicious and enhances one’s enjoyment,” The source, it is critical to point out, was written in Greek, outside the land of Israel.
Greek culture and practices started being influential in the Mediterranean in the final two centuries BCE, and by the time of the Gemara, had become the dominant traditions for all “civilized” people in the known world. When the Mishna was written, for example, all educated Romans spoke Greek, and Latin had become the language of the lower classes. Greek customs were the customs of all civilized people.
Why did people water down wine? One possibility, given in Section I is that certain wines were more likely to cause a hangover. The more commonly suggested solution than the presence of hangover-inducing components, is that wine served as a disinfectant for water that itself might be unsafe.
Today, we know this is true. Drinking wine makes our water safer to drink, and it also helps sanitize the food we eat at meals when we drink wine. Living typhoid and other microbes have been shown to die quickly when exposed to wine. Research shows that wine (as well as grape juice), are highly effective against foodborne pathogens while not significantly weakening “good” probiotic bacteria. In one study, it was shown that wine that was diluted to 40% was still effective against foodborne pathogens, and drier wines were much better at killing dangerous bacteria.
The ancients believed that wine was good for one’s health, even if they didn’t have the faintest idea why this was so. Microbes were only discovered in the 19th century, and ancient medicine was in many respects indistinguishable from witchcraft. Still, it seems hard to deny that Romans and Greeks at least grasped some of the medicinal value of the grape; wines were a common ingredient in many Roman medicines. And given the antibacterial powers of wine, it is obvious that a patient who drank diluted wine instead of water would be helping his body by not adding dangerous microbes when the body was already weakened by something else.
Still, the evidence remains anecdotal.
While the archaeological record is strong in this respect, the lack of textual support, in this author’s opinion, means that there is more evidence that wine was diluted for cultural reasons than because there was a conscious understanding that wine made water safe to drink.
Isaiah Cox, “Wine Strength and Dilution”, The Seforim Blog (31 October 2012) [http://seforim.blogspot.com/2012/10/wine-strength-and-dilution.html]