AD&D 2nd Edition

Sphere: All
Range: 30 yards
Components: V, S
Duration: Permanent
Casting Time: 1 round
Area of Effect: 1 cubic foot / level, 10-foot-square area
Saving Throw: None

When cast, this spell makes spoiled, rotten, poisonous, or otherwise contaminated food and water pure and suitable for eating and drinking. Up to one cubic foot of food and drink per level can be thus made suitable for consumption. This spell does not prevent subsequent natural decay or spoilage. Unholy water and similar food and drink of significance is spoiled by purify food and drink, but the spell has no effect on creatures of any type nor upon magical potions.

The reverse of the spell is putrefy food and drink. This spoils even holy water. It likewise has no effect upon creatures or potions.