How to Store Distilled Water Correctly

Whether you need distilled water for a CPAP machine, you use it for your drinking water, or you buy it for cleaning or appliance filling purposes, you might be wondering how to correctly store your distilled water before and in between uses.

I’ve been buying distilled water for several appliances in my home for years, and I’ve combined my experience as a distilled water user with my expertise in the water industry to produce this detailed resource on how to keep distilled water fresh in storage.

🤔 What’s the Best Way To Store Distilled Water?

Generally, you should take the same approach when storing distilled water compared to storing normal tap water. Distilled water isn’t more susceptible to spoiling once opened – in fact, it’s less likely to go bad in storage than tap water.

The best way to store unopened distilled water is in a cool, dark place, like a cupboard or a pantry. Make sure the water is away from direct sunlight, heat sources, and steam or humidity, and rotate your stock so you’re always using the oldest stock first. That means you shouldn’t end up with old, expired distilled water at the back of your cupboard that you’ve forgotten about.

The best way to store an opened bottle of distilled water or homemade distilled water is in a clean glass container, sealed tightly to prevent contamination from outside sources. Put the container in a sanitized location, ideally a dedicated food storage space like a refrigerator. I recommend glass instead of plastic containers because glass won’t degrade and leach harmful contaminants into the water, which is always a risk with plastic.

✅ Top Tips for Correctly Storing Distilled Water

Here are my top tips and recommendations for storing your distilled water and keeping it fresh:

Switch To A Safe Container

First, if you’ve bought distilled bottled water and you’ve opened the bottle, transfer the contents into a glass, food-grade plastic, or stainless steel container that’s intended for storing water or food. Single-use plastic bottles are more prone to degradation and chemical leaching than reusable containers, so it’s best to ditch the plastic as soon as possible.

Rotate Your Stock

If you’re storing a big batch of unopened distilled water, make sure to rotate your stock so your older bottles get used first. That means you won’t have expired distilled water at the back of your cupboard that you end up throwing out.

Ensure The Container is Sealed Tightly

A tightly sealed container is a must for storing distilled water – or any type of water, for that matter. I recommend using glass bottles with sealed stoppers to keep the water fresh and prevent contamination from airborne impurities.

Store Water in a Cool, Dark Place

Like any water type, distilled water stays freshest and is the least susceptible to contamination when it’s stored in a cool, dark place. I recommend storing your distilled water in a cupboard away from direct sunlight, heat, and humidity. Many folks store their water in a kitchen cupboard, but this isn’t always the best place because kitchens can regularly become hot and humid, especially if you’re an avid cook. A pantry or basement may be the best storage location for you.

Drink Within 7 Days

If you’re drinking distilled water stored at home, I advise drinking it within 7 days. While the water is unlikely to go bad after this time if you store it correctly, it’ll lose its freshness after a few days, so it’s best to drink it as soon as possible after opening the bottle.

🧐 Should You Store Distilled Water in the Fridge?

Many people like to store distilled water in the fridge because of the pleasant experience of drinking cool water rather than room-temperature water. I also think that storing opened distilled water in an enclosed environment like your fridge means it’s less likely to be contaminated by airborne particles in your kitchen.

With that said, storing distilled water in the fridge isn’t necessary for maintaining its purity or safety. Distilled water, when stored properly in a clean, sealed container in a cool, dark place, should remain fresh and suitable for its intended uses without needing to be refrigerated.

📆 How Long Can Distilled Water Be Stored?

You can store distilled water for an indefinite period – as long as you’re storing it properly. Distilled water lacks the contaminants and organic matter that support microbial growth, and it’s much cleaner and purer than normal tap water, so it doesn’t spoil or deteriorate over time.

Of course, as I mentioned, this is assuming that the water is stored correctly. Regularly inspect the water for any changes in appearance, and if you suspect contamination, I recommend replacing the water with a fresh supply to stay on the safe side.

How long does distilled water last in storage once it’s opened? Again, as long as you’ve followed the water storage tips in this guide, your opened distilled water should last indefinitely. However, I generally advise that you store the water for a maximum of 1 year if you intend to use it for appliances. Or, if you’re drinking distilled water, it’ll stay fresh and taste at its best for up to a week, and I recommend drinking it within 3-5 days once it has been opened.

📉 What’s the Shelf Life of Distilled Water?

The shelf life of distilled water is typically indefinite because it doesn’t technically expire although most manufacturers label their distilled bottled water with a 3-5-year shelf life.

Generally, when distilled water is stored in a sealed container, like an unopened bottle, it should last a year beyond its labeled shelf life. With that said, I recommend that you drink distilled water before the best-before date on the bottle so you can enjoy it while it’s still fresh.

🆚 Distilled Water Vs Bottled Water: What Are Their Storage Differences?

Wondering how distilled water compares to regular bottled water, like bottled spring water or normal mineral water?

Distilled water has an advantage over normal bottled water when it comes to the storage period. Generally, because it’s completely free from impurities, distilled water can maintain its quality for an extended period and is less prone to bacterial growth or contamination compared to bottled water (as long as it’s stored correctly in a clean, sealed container).

Normal bottled water is usually sourced from natural springs or purified with various filtration methods. It’s not guaranteed to be impurity-free – and, in fact, it often contains minerals and trace elements that can affect its taste and composition. While regular bottled water is safe to drink and suitable for most everyday purposes, its impurities content makes it more prone to going stale over time, especially if it’s stored for an extended duration.

If I’m being honest, the differences between distilled water and normal bottled water are so minor that, storage-wise, I don’t think it’s worth investing in distilled water instead just for the slightly longer shelf life. Both water types require the same storage practices anyway, so just make sure to rotate your stock regularly and avoid direct sunlight and heat, and you should never encounter an issue with your water in storage.

💯 What’s the Best Container to Store Distilled Water in?

The best container to store distilled water in is a glass bottle with a lid.

Glass bottles are ideal for storing distilled water for a few different reasons:

• They don’t affect the taste of distilled water. Glass is non-reactive and doesn’t degrade like plastics and other materials, meaning it doesn’t impart any taste, odor, or chemicals into the water. That is especially important when storing pure distilled water, which is “hungrier” because of its lack of impurities and may leach contaminants from certain containers.
• They’re impermeable: Glass is impermeable to gases and liquids, so it provides an effective barrier against contaminants in the external environment. This helps to keep distilled water pure over time.
• They don’t leach harmful contaminants. As we touched on above, glass doesn’t leach any harmful substances into the water. The same can’t be said for a plastic container – certain types of plastics can release chemicals, especially when they’re exposed to heat or UV light, which can affect water quality.
• They’re resistant to temperature changes. Glass bottles are resistant to temperature fluctuations, making them suitable for storing both hot and cold distilled water without warping, melting, or degrading in any way. Again, you can’t guarantee this outcome when using plastic containers.
• They’re durable. Glass is a sturdy material that, when handled with care, should last longer than most other storage materials. It doesn’t degrade or break down over time as some plastics can, so it can be used for an extended period.

If you don’t have glass containers on hand, stainless steel containers are the next best alternative. These are more durable than glass and don’t pose the risk of chemical leaching like plastic, but they might give your water a slightly metallic taste.

If worst comes to worst, you can safely store opened distilled water in plastic bottles – just make sure to use a reusable bottle rather than the single-use bottles that distilled water is sold in, since these are flimsier and degrade at a faster rate. Also make sure your plastic bottle or airtight container of choice is free of BPA, BPS, BPF, and other bisphenols that could leach into your water.

📑 Final Word

I wrote this guide because I wanted to provide a helpful, detailed resource that you can return to whenever you have a question about how to store distilled water. If you follow my tips in this article, you’ll be able to store your water safely and avoid the worst-case scenario of drinking contaminated distilled water.