Does Distilled Water Go Bad and After Opening? And in Heat?

As an engineer with a passion for sustainability, I often find myself debunking common myths. Today, I want to address an intriguing question: does distilled water go bad? And, does it go bad after opening or in heat?

Key Takeaways

  • Distilled water doesn’t spoil like food but can absorb impurities from the air.
  • Proper storage extends its shelf life: use airtight, clean containers, and avoid light.
  • After opening, consume distilled water within a few days to weeks for best quality.

If you are concerned that your distilled water may be going bad, keep reading to know what to look for and how to understand if it’s still good or not. This will also depend if the distilled water container was already opened and if it was exposed to heat. Read on!

Understanding Distilled Water

Distilled water is a type of purified water that has undergone a specific process in a water distiller to remove impurities and contaminants. It is created through the process of distillation, where water is heated to produce steam, which is then condensed and collected as distilled water.

Distilled water is essentially pure H2O, as it doesn’t contain any minerals, bacteria, or other impurities. It is free from organic materials and dissolved salts, making it ideal for applications where impurities can cause problems or affect the quality of a product.

The primary purpose of using distilled water is to ensure a high level of purity in various processes and applications. For example, distilled water is commonly used in steam irons and humidifiers to prevent mineral buildup that could clog the appliances.

It can also be used in scientific experiments, pharmaceutical preparations, and automotive cooling systems, where the presence of impurities could impact the performance or safety of the equipment.

Does distilled water go bad?

When it comes to the shelf life of distilled water, there are a few factors to consider. Unopened commercially bottled distilled water can last indefinitely, thanks to careful handling and the use of airtight containers that prevent contamination. As long as the seal remains intact, the distilled water will maintain its purity for an extended period.

Unopened vs. Opened Distilled Water: A Comparative Analysis

Unopened distilled water has a significantly longer shelf life compared to opened distilled water. Once the seal is broken, there is a higher risk of contamination as the water is exposed to air and its surroundings.

However, this doesn’t necessarily mean that opened distilled water becomes unsafe to drink or use immediately. If the water is stored properly, with precautions taken to prevent contamination, it can still be used for an extended period.

Potential Factors Affecting Shelf Life

The shelf life of distilled water can be influenced by various factors, including storage conditions and the prevention of contamination. Proper storage techniques involve keeping the water in a cool, dark place to avoid exposure to light and fluctuating temperatures.

Additionally, using containers made of food-grade materials, such as glass or BPA-free plastic, can help maintain the quality of the distilled water.

It’s essential to avoid introducing contaminants to the distilled water during storage, as this can compromise its purity. Taking precautions such as using clean utensils or dispensers when accessing the water and ensuring proper hygiene can significantly extend the shelf life of the distilled water.

Identifying Spoiled Distilled Water: Key Signs to Watch Out For

While distilled water doesn’t go bad in the traditional sense, it can become compromised or contaminated over time. There are several signs to watch out for to identify if distilled water has spoiled.

1. Discoloration, Odor, and Taste

If distilled water develops a strange odor or taste, it may be an indication of contamination. While distilled water is supposed to taste and smell neutral, a chemical off-smell or an unpleasant taste could suggest the presence of impurities or bacterial growth. Discoloration, such as a cloudy appearance or the presence of particles, can also be signs of contamination.

2. Visible Contaminants in Distilled Water

The presence of visible contaminants, such as sediment, particles, or foreign substances, in distilled water, can be a clear indication of contamination. These contaminants can enter the water during storage or handling and may pose risks to health and the intended application of the water. Therefore, it’s essential to discard the water if visible contaminants are present.

Proper Storage for Distilled Water: Making it Last Longer

To maximize the shelf life of distilled water and maintain its purity, proper storage techniques should be followed.

1. Light Exposure, Temperature, and Sealing in Storage

When it comes to properly storing distilled water, there are several key factors that play a crucial role in extending its shelf life. Light exposure, temperature, and sealing are all important considerations to ensure the longevity and quality of your stored distilled water.

  • Light exposure: While distilled water does not go bad in the traditional sense, exposure to light can cause its quality to deteriorate over time. Ultraviolet (UV) rays from sunlight can break down the molecules in the water, leading to a potential reduction in its purity. To prevent this, it’s important to store distilled water in opaque containers or keep them in a dark, cool place away from direct sunlight.
  • Temperature: Along with light exposure, temperature is another significant factor that can impact the shelf life of distilled water. Higher temperatures can accelerate the growth of microorganisms and promote the development of algae or bacteria in the water. Therefore, it is recommended to store distilled water at room temperature or below to maintain its purity and freshness for an extended period. Avoid storing distilled water in hot areas such as direct sunlight or near heat sources like stoves or radiators.
  • Sealing: Proper sealing of the containers is essential to prevent contamination and maintain the quality of distilled water. Be sure to tightly seal the containers after each use to prevent the entry of airborne pollutants or moisture. This will help prevent the growth of bacteria or the introduction of impurities that can compromise the integrity of the distilled water.

Choosing the Right Containers for Storing Distilled Water

The choice of containers for storing distilled water is crucial to ensure its longevity and prevent any potential contamination. Here are some key considerations when selecting the right containers:

  1. Material: The container material plays a significant role in maintaining the quality of stored distilled water. Avoid using containers made of plastic, as they can leach unwanted chemicals into the water over time. Instead, opt for glass or stainless steel containers that do not react with the water and preserve its purity.
  2. Size: Choose containers that are appropriate for your storage needs. It may be beneficial to have a combination of larger containers for long-term storage and smaller ones for convenient everyday use. This way, you can minimize the frequency of opening and expose the water to air, therefore reducing the risk of contamination.
  3. Closure: Ensure that the containers have secure and reliable closures. Look for containers with tight-fitting lids or caps that provide an airtight seal, preventing the entry of contaminants and maintaining the freshness of the distilled water.
  4. Transparency: While it is crucial to store distilled water in opaque containers to protect it from light exposure, it can also be helpful to have some transparent containers for monitoring the quality of the water. Transparent containers can allow you to visually inspect the water for any signs of discoloration, cloudiness, or contaminants.

Extending the Shelf Life

The Impact of Sterilized Containers

Choosing sterilized containers for storing distilled water can significantly impact its shelf life. Sterilized containers are free from any bacteria or contaminants that can potentially shorten the water’s freshness and safety. By using such containers, you minimize the risk of introducing impurities and maintain the water’s purity for a longer period.

Reduce Exposure to Air

Exposure to air can introduce impurities into the stored distilled water, compromising its quality over time. Reduce exposure to air by following these strategies:

  • Keep containers tightly sealed: Always ensure that the containers are tightly sealed after each use. This prevents the entry of airborne contaminants and maintains the distilled water’s purity.
  • Minimize the frequency of opening: Avoid unnecessary opening of the containers, as each time the container is opened, there is a chance for air and contaminants to enter. Try to use larger containers for long-term storage to minimize the need for frequent opening.
  • Use smaller containers for daily use: To reduce the exposure of the entire volume of distilled water to air, transfer a portion of the water into smaller, conveniently sized containers. This way, only the required amount is exposed to air while the rest remains sealed and protected.

Benefits of Consuming Within a Specific Time Frame After Opening

While unopened distilled water can last indefinitely when stored properly, it is advisable to consume the water within a reasonable time frame after opening. The freshness and quality of the water can degrade slowly over time, especially if not stored under ideal conditions.

To ensure the best taste and purity, it is recommended to consume the open distilled water within a few days or weeks, depending on the storage conditions and quality of the water.

Disposing of Bad Distilled Water: Environmentally-Friendly Approaches

When distilled water reaches the end of its usability or quality, it’s important to dispose of it properly using environmentally-friendly methods. Based on the 6 Rs of sustainability, here are some eco-friendly approaches to consider:

  1. Reuse: If the distilled water is still relatively clean and free from contaminants, consider reusing it for non-consumable purposes. You can use it for cleaning, watering plants, or other suitable applications that do not require high-purity water.
  2. Recycle: Contact your local recycling center to inquire about their policies on recycling distilled water. Depending on the container material and local regulations, it may be possible to recycle the containers along with the remaining distilled water.
  3. Proper disposal: If none of the above options are viable, dispose of the distilled water in a manner that minimizes environmental impact. Ensure that it is poured down the drain or toilet in small quantities, following local regulations and guidelines.

Practical Uses of Distilled Water in Home Appliances

Distilled water is not only suitable for drinking but also has practical applications in various household appliances. Its purity makes it an ideal choice for use in appliances that require water with minimal impurities, such as steam irons, humidifiers, and coffee machines.

Here are some practical uses of distilled water besides drinking it:

  • When used in steam irons, distilled water helps prevent mineral build-up and extends the lifespan of the appliance. The absence of minerals ensures that no residue or scaling forms inside the iron’s steam vents, keeping them clean and unclogged. This, in turn, allows for better steam production and efficient ironing.
  • Humidifiers, particularly those of the ultrasonic type, benefit from distilled water as well. The lack of minerals prevents the formation of white dust, a common issue caused by mineral residue in tap water. By using distilled water, you can enjoy the benefits of a humidifier without worrying about dispersing potential irritants or residue into the air.
  • Coffee lovers will appreciate the use of distilled water in their coffee machines. The absence of minerals prevents the build-up of limescale in the machine, which can affect the taste and function of the coffee maker. Using distilled water helps maintain the flavor profile of your coffee and ensures that your machine operates optimally.

Pros and Cons of Using Distilled Water for Drinking

When it comes to drinking water, the use of distilled water is a topic of debate. Here are some pros and cons to consider:


  • Purity: Distilled water is incredibly pure, free from impurities, minerals, and contaminants. Some people prefer the neutral taste of distilled water and believe that its purity makes it a healthier option.
  • Reduced Risk of Exposure to Contaminants: The distillation process removes potential contaminants, such as heavy metals and chemicals, making distilled water a popular choice for those concerned about water quality.


  • Lack of Minerals: Distilled water lacks essential minerals that are beneficial for our bodies. While most mineral needs can be met through a balanced diet, some argue that the minerals obtained through water consumption are valuable.
  • Potential Leaching of Minerals: Some research suggests that drinking distilled water may cause the leaching of essential minerals from our bodies. However, this is a topic of ongoing scientific debate, and the impact is likely minimal for individuals with a varied diet.

Ultimately, the decision to drink distilled water is a personal one. While it is safe to consume, some believe that the lack of minerals may not make it the ideal choice for long-term hydration. It’s important to consider your individual health needs and dietary intake when deciding on the type of water to consume.


How should distilled water be stored?

Distilled water should be stored in cool, dark places away from direct sunlight, heat sources, and potential contaminants. Use sterilized containers with tight seals to maintain its purity.

Can distilled water become contaminated?

While distilled water is initially pure, it can become contaminated if exposed to air, unclean containers, or other sources of pollutants. Proper storage practices can help prevent contamination.

Is distilled water safe to drink?

Distilled water is safe to drink and is commonly used for various purposes. However, it is important to store and handle it properly to maintain its purity and prevent contamination.


So, there you have it! So, does distilled water go bad? The answer is not a simple yes or no, but rather a nuanced one. Distilled water itself does not go bad in the traditional sense, as bacteria cannot grow in its pure form. However, the quality of the water can be compromised over time due to exposure to impurities from the environment.

Remember, even though distilled water doesn’t go bad like milk or leftovers in the back of your fridge, it’s still essential to store it properly to maintain its purity. Keep it in a clean, airtight container away from direct sunlight and extreme temperatures. And if you’re unsure about the quality of your distilled water, a simple sniff test can give you a clue!

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