Bottles of water are a rare potion. They can be turned into Blessed bottles of water by dropping (NOT MIXING!) them on an altar of the player's patron god, or if they follow no god, an unaligned altar.
Blessed and cursed bottles of water can dipped ( ) with other items to bless or curse the other item respectively. If the item is stacked, the entire stack becomes blessed. This makes it possible to bless 5 Bottles of water with 1, but also to bless hundreds of scrolls or other potions.
Bottles of water have a slim chance of being made by mixing empty bottles with a well or fountain.
There is also chance using Rod of Alchemy to convert any potion to water.