Does Distilled Water Ever Go Bad? What Most People Don’t Know

Distilled water (a type of purified water) does not go bad because it is a type of water. People store this water for many purposes; either for occasional drinking, for a humidifier, or a steam iron.

For whichever reason you keep this water at home, there are some details you need to know. While this purified water doesn’t go bad, it’s not good or fit for use forever.

This article contains important information like the shelf life of distilled water, factors that influence its quality, and how to identify if the water has gone off.

What is distilled water?

Distilled water is a type of purified water that is free of minerals and contaminants, thereby making the water very clean.

This water is made by boiling ordinary water to remove 99.9% of minerals and produce steam. The distillation process is what results in distilled water.

The resulting steam from boiling ordinary water undergoes condensation back into a liquid. Then, the droplets are collected into containers for different uses.

Although this water tastes flat and bland, some people still find it a good choice for drinking water (however, not daily).

Additionally, this is the common type of water that industries use for different production purposes. However, you can have this purified water at home for drinking and to use in household appliances like a steam iron.

Does distilled water go bad?

Distilled water doesn’t exactly go bad, but under the wrong storage conditions, it can become contaminated and unfit for drinking.

Unlike foods that may be perishable, this purified water may not look bad at a glance but you should watch out, especially if you have opened the bottle.

Does distilled water go bad after opening?

Yes, it does.

Just like with every food, when you open a bottle of distilled water, you expose the water to air pollutants that can affect the quality of the water.

In addition, an open bottle of this purified water should be consumed within a week. Otherwise, store it properly in a refrigerator to keep it drinkable for up to ten months.

Does distilled water go bad in heat?

Distilled water that has been kept in heat or an environment that is too warm will become contaminated in no time.

This is why you should keep your bottles of water away from sunlight. Direct heat will speed up contamination and spoilage, especially if you store it in plastic containers.

The heat will speed up the leaching of chemicals into the water and make it unfit for drinking.

Will distilled water go bad if unopened?

Until you open a bottle of distilled water, you can expect it to last for years (at least 2-3 years).

You may keep the water in or outside the refrigerator or freezer. You can also keep it in a pantry or space that shuts out sunlight and heat.

When you store unopened bottles of this purified water properly, you can be sure that the water won’t go bad.

What is the shelf life of distilled water?

The shelf life of this purified water depends on the preparation process it went through.

Homemade distilled water will most certainly not last as long as store-bought water. The homemade variety lasts 3-7 days outside the refrigerator while store-bought water can last up to a year.

However, you should know that either variety of this water is at its best quality for drinking for only a week, after opening.

Therefore, whether it’s homemade or bottled (that is, store-bought), you should drink an opened bottle of this purified water within a week.

On the other hand, an unopened bottle of this purified water can last up to five years if you store it properly in a pantry or freezer.

Can you get sick from drinking expired distilled water?

Drinking distilled water that has gone bad can cause diarrhea, headache, stomach upset, fever, and kidney problems in severe cases.

Moreover, when a person drinks purified water that contains chemicals over a long period, it can result in nervous system disorders and skin discolorations.

How to tell if distilled water is bad

Check the appearance

Cloudiness is a sign that the water has gone bad. Good water is naturally clear, bad water gets cloudy with pathogens or chemical contaminants.

However, cloudy distilled water can be used for household appliances. Be careful to keep it out of the reach of children so they don’t drink it.

Presence of microorganism growth

When your bottle of purified water contains contaminants, it becomes a good breeding ground for the blue-green algae.

Also, the algae thrive with exposure to sunlight. If you notice algal growth or floating algae in your bottle of water, throw it away.

An off smell

Smell has proven to be a reliable sense for detecting spoilage. When this purified water has gone off, it’ll smell different from what it smelled like when it was fresh.

For accuracy, pour the water into a glass cup and smell it. Detecting spoilage by smelling water in the container can be confusing because you might pick up the smell of the container instead of the water.

It tastes off

When this purified water has gone bad, it develops a funny taste. Naturally, like every other type of water, the water is tasteless and even blander.

However, when chemicals and pathogens contaminate the water, it tastes off. If you notice this, discard the water and get a fresh batch of this purified water.

How to preserve distilled water

  • Keep the water away from sunlight
  • Do not leave the bottle of water in the car for too long
  • The best storage containers for this purified water are glass containers
  • This purified water should be kept in tightly sealed containers to keep out pathogens and chemicals
  • Store large quantities of this purified water in high-density polyethylene drums (HDPE). These drums are highly resistant, not prone to rust, they protect the water from sunlight, and they help to keep the temperature of the water stable
  • You can also keep opened bottles of water in the refrigerator
  • In or outside the refrigerator, keep the bottles of water away from other items that have strong odors. Otherwise, the water will take up the strong smells too


Should you refrigerate distilled water after opening it?

Yes, you can refrigerate distilled water after opening it.

Refrigerating this purified water doesn’t affect its quality or extend its shelf life.

Can you store distilled water in plastic jugs?

You may keep distilled water in plastic containers if you’ll use it up in a few days.

However, the best way to store this water is to keep it in glass containers. This is because the chemicals in plastic containers will leach into the water and contaminate it.

Can you freeze distilled water?

Yes, you can.

Keeping opened distilled water in the freezer is the best way to store it and keep it fit for use.

In the freezer, toxic chemicals like carbon dioxide cannot penetrate the water and affect its quality.


Distilled water isn’t so different from ordinary water except for the minerals it doesn’t contain. And just like ordinary water, it doesn’t go bad.

However, open kegs of this purified water will become contaminated if you don’t store them properly.

Therefore, it is essential to keep the water well, away from sunlight and contamination. If you have opened the keg or bottle of water, finish it quickly or freeze it to keep it for longer.

Thanks for reading.

Check Millenora for related articles on food and drinks spoilage and preservation.