No Matter if Tap or Bottled, Can Water Go Bad?

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Mike Roth

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Reviewed by Tara Dodrill
Can Water Go Bad

Here is your question “Can Water Go Bad?”, be answered. The short answer to that question as well as the query, “Does bottled water expire” are both, “yes.” Keep Reading to find out how to store your bottled water and water cooler jugs long-term. Even pure water from the tap that does not come from plastic bottles can go bad when not stored in the precise way advised by scientists to keep it potable.

Read About Can Water Go Bad?

Does Store-Bought Bottled Water Go Bad?

Store water, despite being marketed as pure and refreshing, is not immune to spoilage. It has a limited shelf life due to various factors, including bacterial contamination, the growth of microorganisms, and the degradation of plastic packaging materials. Understanding these reasons for storing water properly is crucial for ensuring the safety and quality of drinking water. Use the dates on water bottles only as a guide, not a point of fact. Old bottled water might be safer to drink than a newer container that has been contaminated.

In Short:

Bottled Still water from the store expires in 2 years while sparkling in 1 year.
These bottles are made from PET, which can leach toxic chemicals into the liquid when it is expired or exposed to heat.
Studies found that BPA-free Bottles are less safe than hoped.

Why Does Bottled Water Go Bad?

Bacterial contamination is a significant concern for the spoilage of stored bottled water. Water can contain bacteria from various sources, including the bottling process, handling, or contamination during storage and transportation – even before its expiration date. These bacteria can multiply and form biofilms over time, leading to unpleasant tastes, odors, and potential health risks when consumed past the expiration date.

The growth of microorganisms is another reason why store-bought unopened bottled water can spoil. Microorganisms such as bacteria, molds, and yeasts can survive and thrive in water if provided with suitable conditions. These conditions include warmth, sunlight, air exposure, and certain nutrients available in water. For example, the presence of organic matter or trace nutrients in bottled water can promote microbial growth when not kept in a cool place.

Degradation of plastic packaging materials can infuse dangerous chemicals into even high-quality water can negatively impact your immune system. The chemicals, such as high-density polyethylene, can cause nonylphenol, which is an endocrine disruptor, to leach into the slightly permeable water bottle.

Avoid reusing bottled water or leaving the open container partially consumed to help them remain safe to drink until their expiration date. Reusing bottled water or leaving the drink partially consumed promotes bacterial growth even before expiration dates have passed.

Bottled Water Expiration Dates

The date you find on almost all bottled water is more of a rule of thumb than something you can rely on. As you never know if the plastic water bottle you buy is always stored correctly and will have a long shelf life.

The more often the bottled water is transported, the more likely it is exposed to excessive heat or direct sunlight -such as being left in hot cars for too long. That will start a leaching process before the expiration date is reached. 

The National Library of Medicine (NIH) found that PET plastic when kept in bottled water long-term, the water bottles can leach toxic chemicals into the liquid when exposed to heat. Temperatures in the summer can heat cars, and enclosed storages like garages, up to 65°C. (149°F). And so does your bottled water.

When bottled water has a strange taste, it’s probably past its expiration date and not safe to drink. Never drink expired water if it shows signs of bacterial contamination, even if the expiration dates have not yet passed on plastic water bottles. It’s the plastic that the water comes packaged in, usually polyethylene terephthalate (PET) for in a retail plastic bottle and high-density polyethylene (HDPE) for water cooler jugs. So, technically, it’s the bottle that goes bad making it not safe to drink, not the water.

When properly stored, the shelf life of bottled water is two years, and sparkling water bottles have an expiration date of 1 year. Plastic bottled water expires in 2 years and is no longer safe to drink. When expired, the bottle is unsafe due to its leaching process. Remember, when stored improperly, it will cause expiration dates on water to be lessened, even when still in a clean container.

Why Tap Water Goes Bad

The expiration date on retail bottles of tap water is, when appropriately stored, six months due to chlorine and Chloramines. [12]

Uncovered Tap Water 

Water in an open glass stays good for around two days as chlorine prevents colonies of bacteria and algae from growing. After 12 hours, it starts to smell and taste strangely. That comes from the change in pH value that happens when carbon dioxide gets released back into the air from the liquid. But that water, as strange as it tastes, is safe to drink.

Water stored outdoors and uncovered is likely to be infected with mosquito eggs, bacteria, and other life forms.

Bottled Tap Water

After six months, the chlorine will probably be dispersed so that algae and bacteria begin to grow and contaminate the water within that process. The growth speed will immensely increase if the bottled water is stored in a warm and sunny place.

When Your Water Went Bad

You take a sip of your water and realize an odd taste. Better purify it through boiling or one of these methods: How To Purify Water.

Risks of Drinking Spoiled Water

  • Drinking expired water from heated plastic bottles will start filling your body with microplastics. [3]
  • BPA mimics estrogen, an essential hormone for reproduction and bone density in women. In men for sperm count, sex drive, and erectile function. BPA is also linked to neurological problems and may cause multiple cancer types! [45]

Where Store Your Water Then?

Water should always be stored, protected from direct sunlight and UV light, and in a cool place. Also, ensure it can’t come in contact (sometimes through the air) with your cleaning chemicals.

When you want to store water long-term, it should always be stored in food-grade containers. When purified before, it will last even longer. Learn more about that here: How To Purify Water.

Kind of Storage Duration to contamination Uncovered in the outside 1-3 Days Sealed Vessels (Bottled Water)6-12 Month Purificated Water and sealed in food-grade container2 Years when stored properly

Aluminum bottles are an excellent choice for storing drinking water. When stored in high-quality aluminum containers, liquid can stay suitable for up to 50 years.

But many other materials are also appropriate:

  • Glass
  • Stainless Steel
  • FDA-approved food-grade Storage
Kind of StorageDuration to contamination
Uncovered in the outside1-3 Days
Sealed Vessels (Bottled Water)6-12 Months
Purified Water and sealed in a food-grade container2 Years when stored properly

Other Infos about Long-Term Storage of Water

  • If you’re a prepper and want to store a lot of Bottled water in your basement or somewhere the water is safe from UV light, refill the containers every 12 months.
  • You can add a few drops of unscented bleach or plain into contaminated water to make it safe again
  • Label your water container with the filling date so you have an overview.

Last Words From me

When you want to store water for a long-term scenario that may occur, you’re good to go with our prepping list we created for you here: Most Essential Prepping List