How Long Does Distilled Water Last?

distilled water for drinking

How Long Does Distilled Water Last?

How long does distilled water last? The answer to this question depends on the purpose you’re using it for.

If you’re using distilled water for home appliances, a sealed bottle of distilled water can last indefinitely. A good idea is to use it 3 to 5 years after production as distilled water does not just go bad on its own just like plain water.

Once opened, you can still use it for one to two years with good care. If you’re planning to drink it, it is best to finish it within a week or so. It might start to smell a bit stale after that time. This smell hasn’t got anything to do with the quality, but it still might be a good idea to order a new batch.

In this article, we are going to look at distilled water, what it is and how to store it for a prolonged shelf life. We will also discuss if it is safe to drink distilled water and how can you tell if it goes bad during storage or regular use. So, let’s take a look.

What is Distilled Water?

Distillation is one of the most popular methods, alongside osmosis, filtration and deionization, to purify water. This process turns water into water vapors by boiling. These vapors are than condensed in a new container.

These are two types of impurities in a substance, volatile and non-volatile. The first set of impurities can be removed by the process of evaporation. As per the second, they are left behind as soon as we change the container for condensation. We are than left behind with impurity-free distilled water.

Does Distilled Water Go Bad?

Just like ordinary or plain water, distilled water does not go bad on its own. It does not spoil which makes it suitable for a long period of time. However, packaging and environmental factors are two things that can greatly affect the quality and shelf life of your distilled water.

Once opened, distilled water comes regularly in contact with the outside air. This process tends to increase the conductivity of distilled water with the passage of time, making it susceptible to an increasing amount of contamination.

It also tends to absorb carbon dioxide during this process which will increase its acidity. Having said that, distilled water is originally free from any kind of impurities. It means that this contamination will still be considerably less than plain water.

Packaging, on the other hand, can greatly affect the quality and shelf life of your distilled water. Distilled water normally comes packed in plastic containers which are susceptible to seeping in unwanted chemicals. These chemicals, once inside the distilled water, can greatly deteriorate its quality at a rapid rate.

How to Tell if Distilled Water has Gone Bad?

It is very difficult for a commercially produced distilled water to go bad. It has already passed through a rigorous purification process, removing all the impurities and nutrients required for microbial growth. Combine it with proper storage and it should be fine for drinking as well as other purposes.

Having said that, if you feel that the smell or taste of your distilled water has changed significantly, it is better to discard it. You should not use it for drinking purposes but if you intend to use it in your home appliances, you can still do that without any issue.

Distilled water can also change its color due to impurities. These impurities, such as dust particles or small animals, can get inside an open water bottle and make it unfit for human usage.

Lastly, if you have left the distilled water bottle open for some time, you might observe green algae starting to grow on its bottom. This can happen especially if you have left the container under sunlight. This is a clear indication of distilled water going bad and you should throw it away at the earliest.

Can You Drink Distilled Water?

Distilled water is perfectly safe to drink, including for dogs. Distillation only removes all the impurities and almost 99 percent of minerals. You might know that a lot of beverages and soft drinks contain distilled water in their production.

It might taste as bland or flat as there are no flavor-imparting minerals, such as calcium or sodium, left behind. However, you live in an area where tap water is highly contaminated, it might be a good idea to rely on distilled water.

It is important to mention here that relying only on distilled water means that you’re missing on a lot of important minerals. It includes micronutrients like potassium and other electrolytes that are needed for growth, energy provisions and other vital functions in your body.

Drinking only distilled water can also cause an imbalance in your body regarding pH, minerals and electrolytes. Distilled water does not have minerals of its own, so it tends to get them from substances in its vicinity to maintain a balance. This includes minerals in your body, such as your teeth.

It is therefore a good idea to combine distilled water with other water sources for your drinking purposes. This will keep your diet balanced and help you stay protected from any kind of unwanted health issues.

What is Distilled Water pH?

The pH scale is a loose measure of a presence of hydrogen ions in a solution. An increase in pH means that the concentration of hydrogen ions in the solution has decreased and vice versa. The pH scale varies from 0 to 14, with zero being perfectly acidic and 14 being perfectly basic.

In theory, pure distilled water should have a neutral pH, 7.0.The process of distillation removes almost all the ions, including nitrates and carbonates, from distilled water and we are only left behind with pure H2Ohaving a perfectly neutral ph.

The reality, however, is quite different. It is because as soon as water comes in contact with air, it tends to absorb carbon dioxide from the atmosphere. This changes its perfectly neutral pH to acidic, shifting to a value of 5.8.

It is because of this reason that even though a freshly produced batch of distilled water is pH neutral, it tends to change its pH levels to acidic a few hours after production.

How to Store Distilled Water?

The storage method of distilled water is pretty much similar to any other types of water. You should always keep an unopened bottle of distilled water away from sunlight, in a cool, dry place. A kitchen pantry or a storage cabinet can serve as an ideal place for this purpose.

Once opened, it is recommended to seal the bottle tightly after every use. This will keep the unwanted chemicals away and help prolong the shelf life of your distilled water. Make sure to follow this step every time or your distilled water might get contaminated with unwanted chemicals.

For Drinking Purposes

If you’re storing distilled water for drinking purposes, start with by choosing a glass container. You can choose any suitable glass tank, many of which comes with home water distillers, for this purpose. A plastic bottle can also do the job as long as it is BPA free.

Some users tend to store distilled water for emergency purposes. If you’re one of them, it might be beneficial to use a mix of large and small containers. You should make sure that these containers should be made of such kind of material that is deemed fit to come in contact with food items.

For Home Appliances

Distilled water comes stripped of minerals, making it highly suitable for cars and other household appliances. This includes your steam iron, fish aquariums, car cooling systems and much more.

Here are some of the key points one should keep in mind while storing distilled water for home appliances:

  • Keep the water bottle away from paint thinners, gasoline and other hazardous chemicals
  • Use small glass containers if you plan to consume it immediately after storage
  • Use highly density polyethylene containers for long term storage

For Industrial Processes

For obvious reasons, industrial users can make no compromise when it comes to the quality of distilled water. These are the users who are going to make a handful of products out of distilled water and use it in their expensive machinery, so even a slight trace of impurity can harm their purpose.

Start with by choosing stainless steel containers for storing distilled water for industrial purposes. They might come as an expensive alternative to glass or plastic containers, but they can also provide you with high-class purity levels.

Stainless steel containers protect distilled water against harmful elements at different stages of storage. It includes evaporation, absorption of carbon dioxide and build up of algae that is enhanced by the direct exposure to sunlight.

Frequently Asked Questions

What is the difference between normal water and distilled water?

Normal water is the type of water that contains all the minerals and impurities. It might include bacteria or germs that can have a harmful effect on your body. Distilled water, on the other hand, is free from all minerals and impurities after undergoing the process of distillation.

Can bacteria grow in distilled water?

Distilled water is pure H2O which means that it lacks all the other elements needed for the growth of living things. It means that if it is stored properly and sealed tightly, distilled water should be free from any kind of bacterial growth.

However, once opened or left unsealed, it comes in contact with the outside atmosphere. This leaves a chance for dust, bacteria and other elements to come inside the water bottle. You won’t be able to see them with your naked eye but yes, bacteria can grow in distilled water.

Does distilled water stay distilled after opening?

Yes, it does. Just like any other type of water, distilled water stay distilled even after you’ve opened the water bottle. You can use an opened bottle of distilled water within a week or so after opening. Those who’re planning to use it for other purposes can do so within 3 to 5 years with good care.

Does distilled water help lose weight?

Distilled water does not help lose weight. Distillation is a process that removes impurities and other types of minerals from plain water. But it does not add or remove anything from the calorie count of water that is actually zero.

Should you refrigerate distilled water after opening?

It is recommended to store distilled water in a dark, cool place away from sunlight. Refrigerator serves as an ideal place for this purpose since it keeps the heat away from it.

It is however important to mention here that refrigeration has no direct impact on the shelf life of distilled water. It will only keep the sunlight away that help keeps it pure and free from unwanted elements in the atmosphere.

Is distilled water in plastic jugs safe?

Distilled water can become contaminated if stored in a plastic container for a long duration. The reason behind it is that this type of water, being mineral free, tends to leach chemicals in from the plastic. It is therefore recommended to use glass containers for storing distilled water for a longer period of time.

Is distilled water good for hair?

According to a study conducted in 2013, there was no link found between the type of water used for washing your hair and the health of follicles. Therefore, you can wash your hair in shower with the regular type of water and leave distilled water for other purposes.


Distilled water can last for a long period of time with proper care. You should store it in cool, dry places away from the sunlight, with pantry and refrigerator as the two ideal places for this purpose. Always keep your distilled water bottle sealed after usage and you won’t have to worry about it going bad in the near future.

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