Does Distilled Water Go Bad? How Long Does It Last?

logo by Editorial Staff | Updated on December 17th, 2022

Are you wondering if distilled water has an expiration date? Have you ever asked yourself, “How long does distilled water last?” If so, this blog post is for you. In this article, we’ll cover the shelf life of distilled water, how to store it properly, and what factors may cause it to go bad. Read on for all the answers!

Does Distilled Water Go Bad?

Distilled water is a great choice for both drinking and home appliance use, and it’s known to last indefinitely when stored properly. Unopened distilled water has no expiration date and its shelf life is typically several years.

distilled water

Once opened, it can easily last for a year or two if taken good care of. Additionally, humidifiers can help make the air feel warmer and improve sleep on cold winter nights. However, if you plan to drink distilled water it may be best to discard it and purchase a fresh bottle as it can leach minerals from the metal container in which it’s stored.

Distilled water is actually tasteless, so its lack of flavor may take some getting used to. Ultimately, distilled water is a great choice for both drinking and home appliance use and can last for many years when stored properly.

Bottled distilled water (unopened)5+ years
Bottled distilled water (opened for appliance use)1+ years
Bottled distilled water (opened for drinking)4 – 7 days
Home-distilled water4 – 7 days

To summarize, it depends. If the container or jug is not opened, it should last for many years. It’s an excellent place to start if the label contains an expiration date. It typically lasts 3 to 5 years from the date of manufacturing. Of course, the water should be safe for a few months after that.

How Long Does Distilled Water Last Once Open?

The usage of opened distilled water determines its shelf life. If you intend to drink the water, you should consume it within a few days to a week of opening the container. However, if you use it for household appliances, it will last up to a year after opening if properly stored.

Does Distilled Water Degrade in Hot Weather?

To keep your distilled water from turning bad, keep it away from direct heat and sunshine. When distilled water is exposed to direct sunshine, it deteriorates faster, especially if stored in plastic containers.

This is because if the environment is warm, it is easier for the plastic compounds in the container to leak into the distilled water.

Is It Necessary to Refrigerate Distilled Water Once It Has Been Opened?

After opening, distilled water does not need to be refrigerated. However, if you choose to do so, it must be treated like any other bottled water. We’ve all experienced how wonderful a cold glass of water from the fridge can be at the end of a long day.

Distilled Water Shelf Life

As the distilled water is exposed to air, the conductivity of the water naturally increases over time, and some contamination occurs. However, because distilled water is so pure, contamination will be limited compared to regular mineral water.

To that end, the container in which you store your distilled water will invariably increase or decrease the shelf life of your water. – Plastic containers, for example, may rapidly leach undesired compounds into distilled water, reducing its purity.

What is Distilled Water?

Distilled water is a type of purified water that has been boiled and condensed back into a liquid form. It is free of minerals, salts, and other contaminants, making it a great choice for drinking, cooking, and cleaning. Distilled water is also commonly used in home appliances like humidifiers and water purification systems.

How It Is Made

Some believe that it is the cleanest water on the planet. However, all water, whether from a natural spring, an artesian well, or a conventional tap, may include trace but harmless levels of minerals, bacteria, pesticides, and other pollutants.

Distillation removes all of the contaminants from the water. Distilled water is steam that has been cooled and restored to liquid form from boiling water. Distillation also eliminates 99.9% of the minerals dissolved in water.

How to store Distilled Water 

The fundamental storage recommendations for distilled water are similar to those for “plain” water. First, keep the unopened bottle or container in a cool, dry location away from direct sunlight. Then, while you’ve opened it, remember to keep the container well shut when not in use.

Distilled Water Storage for Home Appliances

Let us now discuss the storage of water for reasons other than drinking. If this is the case, keep the product away from solvents and chemicals such as gasoline, paint thinners, home cleaners, and dry cleaning chemicals. As an added precaution.

A high-density polyethylene container is an ideal choice for long-term distilled water storage. But, of course, buying one is pointless if you’re only storing a few ounces at a time for ironing.

Distilled Water Storage for Drinking

If you’re distilling water at home for drinking reasons, a glass container for water is ideal, as many home water distillers have a glass tank. However, a BPA-free plastic food-grade bottle would suffice.

If you need to preserve some water in an emergency, one large or two smaller containers will suffice. But, again, be sure they’re designed to come into touch with food. The notion is that distilled water will remain safe eternally if tightly packed, but I’d still change the water every several months, particularly if it is in a plastic container.

How to Tell If Your Distilled Water Is Contaminated

Distilled water is almost entirely free of minerals and salts, and if these contaminants are present in the water, they should be removed prior to drinking. To tell if your distilled water has been contaminated, look for green algae, as a blue-green alga can form when nutrient-rich water is exposed to direct sunlight.

Additionally, clean water should have a clear appearance so cloudiness could also be an indicator of contamination.

Finally, it’s important to note that commercially distilled water does not go bad very easily since it has undergone the distillation process to remove impurities, minerals, and other contaminants. If you plan to drink the distilled water, it’s probably best to discard and purchase a new jug after about five years.

How Can I Make Use of Old Distilled Water?

You can utilize it in the same manner as before. However, distilled water must have a shell life for several reasons.

To begin, food and beverage makers must include expiry dates on labels; otherwise, it causes worry among responsible organizations and customers when individuals are unable to locate an expiration date. Something that expires indicates that it is food or drink. Something that does not expire is not considered edible.

Second, water is one of the basic components that comprise our bodies and most of our world. In principle, pure H2O is stable, and if maintained in a properly safe, non-reactive container, it will remain unaltered for thousands of years.

The container, on the other hand, is frequently the source of the problem. For example, if distilled water is stored in plastic bottles for an extended period, such as tens of years, a minuscule amount of plastic may seep into the water.

Also, if the distilled water container was left open and the water became contaminated, certain germs may begin to increase there. These are the two most likely reasons why distilled water might become bad.

Is It Possible to Use Expired Distilled Water in a CPAP Machine?

Distilled water beyond its expiration date can still be used in a CPAP machine as long as it has been properly kept and there are no contamination symptoms.

Keep in mind, however, that if your distilled water has gone bad, it is easy to detect. You should not use it if it has a blue-green tint, if it smells strange, or if you detect a strange flavor – which may not apply to household appliance usage.

Is It Okay to Use Old Distilled Water in a Humidifier?

The same regulations apply when using expired distilled water in a humidifier as when using fresh distilled water. A humidifier is used to add moisture to the air to improve breathing. This technique, however, will be useless if you use polluted water. However, as you know, not all expired distilled water is hazardous.


We addressed the question in this article. “Does distilled water go bad” and other related issues, such as how long distilled water can last or how to detect if your distilled water has gone bad.


Editorial Staff

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