Pure water doesn’t “go bad” like food, but its quality can degrade over time due to external factors. This degradation may affect its taste, smell, appearance, or safety. Understanding these processes is important for maintaining water quality during storage.
Factors Affecting Water Quality
Water quality diminishes during storage due to several factors. Microorganisms, such as bacteria and algae, can proliferate, especially when exposed to light or stored improperly. This microbial growth often leads to noticeable changes in taste, smell, and appearance. Chemical leaching from containers is another factor. Materials from plastic bottles, for instance, can migrate into the water, a process accelerated by heat or direct sunlight. Water also acts as a universal solvent, absorbing gases like carbon dioxide, which can result in a stale taste. It can also absorb odors from its environment. Evaporation, particularly in open containers, can concentrate minerals or impurities, further altering its composition.
Water Types and Their Shelf Life
The shelf life of water varies considerably depending on its type and processing. Treated tap water, containing chlorine, has a shorter shelf life once it leaves the tap. Chlorine dissipates, and without this disinfectant, microbial growth can occur. It generally remains safe for several days, though taste may change. Bottled water often carries “best by” dates, which relate to quality rather than safety. These dates are due to potential plastic leaching or absorption of environmental odors. Purified and distilled water, with minerals removed, are less prone to microbial growth. However, their purity makes them more susceptible to absorbing contaminants from containers or air. Untreated water, like well water, is most vulnerable to microbial contamination and should be regularly tested, as it lacks municipal treatments.
Recognizing Impaired Water Quality
Identifying water with compromised quality involves observing several indicators. Visual cues like cloudiness, suspended particles, or unusual discoloration, such as a green tint from algae, suggest degradation. The water’s smell can also provide clues; common off-odors include moldy, musty, sulfur (rotten egg), plastic, or chemical scents. Taste changes are another sign. A flat or stale flavor can result from lack of oxygen, while a metallic, chemical, or unpleasant plastic taste indicates contamination. While some changes, like staleness, may not pose health risks, microbial growth or chemical contamination can indicate potential harm. Avoid drinking water that exhibits significant alterations in appearance, smell, or taste, as these signal contamination.
Proper Water Storage
Maintaining water quality during storage requires careful attention. Selecting the right container is important, favoring clean, food-grade, and airtight options. Materials like glass, BPA-free plastics (HDPE or PET), and stainless steel are suitable, as they are less likely to leach chemicals. Store water in a cool, dark place, away from direct sunlight, heat, and chemicals that can emit odors or fumes. Proper hygiene, including clean hands and dispensing methods, prevents contaminant introduction. For long-term storage, rotate water supplies every 6 to 12 months to ensure freshness. To prevent backwash contamination, avoid drinking directly from large storage containers.