This spell makes spoiled, rotten, poisonous, or otherwise
contaminated food and water pure and suitable for eating and
drinking. 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 magic potions.
Note: Water weighs about 8 pounds per gallon. One cubic foot
of water contains roughly 8 gallons and weighs about 60 pounds.