Water itself does not become unsafe to drink when frozen in a freezer. Freezing water is actually a method of preservation, as low temperatures inhibit the growth of bacteria and other microorganisms that can cause spoilage.
However, the quality of the frozen water can deteriorate over time due to factors such as freezer burn or absorption of odors from other foods in the freezer. Freezer burn occurs when the water molecules in the ice crystals sublimate, meaning they transition from a solid to a gas without going through the liquid phase. This can result in dry, discolored patches on the surface of the ice, affecting the taste and texture of the frozen water.
As a general guideline, it is recommended to consume frozen water within a reasonable timeframe to ensure the best quality. While there are no specific safety concerns associated with long-term freezing of water, it is a good practice to consume frozen water (such as popsicles) within a few months for optimal taste and texture. Proper packaging, such as using airtight containers or freezer bags, can help minimize the risk of freezer burn and maintain the quality of the frozen water.
If you notice any off flavors, odors, or significant changes in the appearance of the frozen water, it is best to discard it to ensure the highest level of food safety and quality.