I ran across this short article about purifying water (against bacteria only).
Offered by Steve.
Wine Treated Water - Since ancient times, in countries like Israel, Rome and (more recently) France, water was too polluted to drink untreated. By mixing 1 part red wine to 3 parts water, sufficient purification was achieved. For killing bacteria in laboratory conditions, red wine ranked 3 to 4 times more effective than pure alcohol or tequila. The effective ingredient is believed to be phenol compounds enhanced from charred wood of the wine-aging casks. This is important because the phenol compounds appear to be related to sulfur drugs previously used in basic antibiotics.
(Source: Dr. Trichopolou, British Medical Journal discussing the Greek Villager's Diet.)