Can Distilled Water Go Bad or Expire? How Long Does It Last?

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Whether you use distilled water for drinking purposes or other cooking and cleaning purposes, you are probably wondering, ‘Does distilled water go bad?

You may have a case of distilled water bottles lying around in the kitchen, leaving you concerned if it needs to be chucked out after some time.

Short answer: Yes, distilled water does go bad, but it can last a lot longer than you’d expect if kept in proper conditions and depending on what you will use it for.

Read on as we talk about distilled water and how long it can last.

Does Distilled Water Go Bad?

As we mentioned, distilled water does go bad after some time. While water doesn’t spoil, environmental factors affect water purity, including air pollutants or the packaging process.

So technically, plain water doesn’t go bad, but it becomes contaminated, deeming it unsafe for drinking. Even if the distilled water is not meant for drinking purposes, you wouldn’t want to use contaminated water at all.

How Long Does Distilled Water Last?

Distilled water can last long, depending on certain factors. The lifespan of distilled water will significantly depend on how you use and store it.

You can also find the best-by label of your bottle to give you an idea of how long it can last.

So, how long does distilled water last, exactly?

On average, here is the varying shelf life of distilled water:

  • An unopened bottle of water can last for 3-5 years or more
  • Opened bottled water can last for over two years when used for home appliances
  • Drinking distilled water in open bottles can last between 4-7 days, sometimes less
  • When distilling water at home, it can last between 4-7 days, sometimes less

With drinking water, we noticed that different factors would affect its properties, such as:

  • Storage temperature
  • Light exposure
  • The bottle or container it’s kept in
  • Air and surface exposure
  • Any contamination with mouth bacteria

But what about the people who say bottled distilled water can last indefinitely?

This is true since it was poured and sealed in a relatively clean environment. However, this only works if it were unopened and in an airtight environment where it can never be contaminated.

We know it may be challenging to maintain such conditions!

Even if a bottle can last for years beyond the expiration date, you should consume it at one point, then replaced it with a fresh batch. That’s is because storing it for too long will most likely affect the water’s taste. (*)

The same would go for home distilled water, lasting for years if produced and bottled in a very sterile environment. However, it takes a ton of effort and we don’t think it’s worth the trouble. (*)

We recommend consuming the water within the week and distill more to drink or use the next time it’s needed.

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How To Tell If Distilled Water Is Bad

How can you tell if distilled water has gone bad? Watch out for these signs:

Presence of Green Algae:

Blue-green algae is a contaminant, forming when nutrient-rich water has been under direct sun or light exposure.

While it doesn’t have nutrients or minerals, contaminants may go inside an unopened water bottle, creating the optimum environment for algae. Impurities would appear, especially when storing distilled water near or under direct sunlight.

If ever you see blue-green floating sediments or scums, this indicates an algae infestation, and we recommend you to throw the water away.


As with all types of water, clean water needs to have a clear appearance, particularly if you plan to drink it.

We urge you to never drink water that looks cloudy, as this means some chemicals and pathogens contaminated your water.

If you plan to use cloudy bottle for home appliances, you can do so without worry, as long as there are no algae around. If accompanied by other signs, this is how you can tell if your distilled water is off.

Suspicious Smell

Any suspicious or foul smell in food and drinks is NOT a good sign. That includes off smells in distilled water. However, water may pick up the smell from the bottle, so check for foul odors more accurately by pouring distilled water in a glass to smell it.

If there is a weird smell, throw it away and replace it with fresh and clean distilled water.

Chemical “Flavor”

We know that if distilled water smells odd, then it will most likely taste off as well. Pure distilled water has no distinct taste, and it would be bland (like plain water) since there are no more minerals in it.

If you ever sense a chemical taste to it, the water is NOT pure anymore, and it may still be perfectly fine to drink. It may have just picked up contaminants in the air or surrounding smells, or it has been exposed to oxygen and sunlight, causing impurities to break down and leave a weird taste.

When we experience even just one of the mentioned signs, we throw the water away immediately. And you should do the same as well!

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How to Store Distilled Water

Now that you know more about bad distilled water and how long tightly sealed bottles last, the next question is storing it. We share tips on storing the distilled water properly to lengthen its storage shelf life:

No Direct Sunlight

Keep your distilled water away from direct sunlight, especially when they are correctly stored in plastic bottles or a container. The sunlight would disintegrate plastic, causing solvents and chemicals to leak in the water, deeming it unsafe to drink distilled water.

The place you store it in should also maintain a low and stable temperature. We believe that kitchen cabinets and pantries are the best storage option.

Use the Proper Container

You will need to ensure that your distilled water is stored properly and in a quality container to preserve its quality.

We recommend storing it in high-density polyethylene (HDPE) tanks or drums for large quantities of water. Be sure that the container is BPA-free food-grade quality.

HDPE tanks aren’t prone to rust, maintain cool water, protect it from light exposure, and are resistant to impact so they don’t fall easily. Even then, always keep the container away from sun exposure and in a cool, dark location.

For smaller quantities of water, store them in a glass container rather than a container made of plastic. If you do store it in a plastic container, be sure you use plastic BPA-free bottles.

What we do is to search online or reuse glass containers when looking for a free food-grade bottle or container.

Make sure that you keep the container sealed to keep the contaminants away and for the water to stay pure.

Keep It Away from Solvents or Smelly Materials

Just like all kinds of water, distilled water would pick up any surrounding smells. That doesn’t affect the water purity or deem it unsafe for appliances like the steam iron, but you don’t want to deal with smelly water.

Store your bottle in a pantry without any materials with strong odors, like household cleaners, cleaning chemicals, paint thinners, and the like.


Besides the pantry, we also store distilled water (like purified water) in the refrigerator, which is a cool and dark place. While it won’t extend the storage shelf life of distilled water, it can help keep it protected from sun exposure.

Frequently Asked Questions

Here are a few frequently asked questions on distilled water shelf life:

Wrapping It Up

When using distilled water, you have to ensure that you store it well, whether using it at home for drinking or appliances.

We hope you keep this information in mind as you use and store bottled water. Do keep this information in mind, especially when it comes to storage, so you won’t have to worry about your water’s expiration date or if it has gone bad.

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Up Next: Bottled Water Shelf Life: Does It Go Bad or Expire?

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