There is a lot of buzz around distilled water. If you are one of those people who have taken a keen interest, a question you might have is ‘does distilled water go bad?’
You might also wonder about the shelf life of distilled water if you’ve kept a bottle or two for a while now. You’ve come to the right place—we’ll tell you everything you need to know including how to check for quality and tips for storing your distilled water.
Does Distilled Water Go Bad?
Distilled water, like other types of water, does not go bad or spoil. However, environmental factors such as pollutants in the air and the process of packaging can greatly affect the purity of water.
So, while your water will not go bad, it can become contaminated, making it unsafe to drink. Even if you plan to use distilled water for other purposes other than drinking, we doubt that you would want to use contaminated water.
Proper storage goes a long way in keeping distilled water in its purest form.
How Long Does Distilled Water Last?
Distilled water will last indefinitely if it is stored correctly and no contaminants come into contact with the water.
Bottled distilled water usually comes with a best-before date. As long as you have stored the water properly, it should still be good to use even past this date.
The good news is that you do not need any special equipment or complicated methods of storing water. You can simply store it in the fridge or pantry away from direct sunlight, and of course, in a clean container.
So, how long does stilled water really last? Well, if you are looking to use it in your home appliances, we’d give it about 24 months but if the water is for drinking, it is best to finish an opened bottle in a day or at most a week for a larger bottle.
Of course, distilled water is best in its purest form and you can keep it this way by observing simple but important storage procedures.
The table below gives you a quick snapshot of how long you can expect your distilled water to last.
Distilled Water Shelf Life
|Opened bottle of distilled water||9-12 months||
3 days-1 week
Unopened bottle of distilled water
Now, let’s talk a bit about how to tell if distilled water has gone bad.
4 Tips To Tell If Distilled Water Has Gone Bad
Distilled water has been stripped of minerals and contaminants and tastes bland. So, just tasting the water alone might not be enough to tell you whether it has gone bad.
Still, your senses are the best way to check the quality of your water. Use these tips to tell if your distilled water is good to use or needs to be tossed out.
1. Green algae
A blue-green alga is a form of contaminant that forms when nutrient-rich water is exposed to direct sunlight.
Distilled water might not have nutrients or minerals but if you leave the bottle open, contaminants can get in and create the perfect conditions for algae, especially if you store the water in the way of direct sunlight.
If you notice blue-green floating scums or sediments in the water, this is an algae infestation and it is time to discard the water.
Clean water should have a clear appearance. Sure, you can use cloudy distilled water in your home appliances without worrying too much.
But, if you have taken to drinking distilled water, it is definitely not a good idea to consume water that looks cloudy. Cloudiness is usually a sign that pathogens or chemicals have contaminated the water.
3. Off smell
An off-smell on any food or drink is never a good sign and the same goes for distilled water. Sometimes, water can pick up the smell of the bottle and you might mistakenly think that the water is not good to use.
For a more accurate judgment, we recommend that you pour some of the distilled water into a glass and take a whiff. If the water has a fishy smell, then it is time to toss it out and replace it with fresh water.
4. Chemical taste
If the water smells off, chances are good that it also tastes bad. Pure distilled water does not have any distinct taste; this variety of water actually has a bland taste because all the minerals have been stripped away.
So, if your water has a chemical taste, it is probably no longer pure. The water might have picked up surrounding smells and contaminants in the air. Exposure to sunlight and oxygen will cause these impurities to break down, resulting in the water developing a strange chemical taste.
Tips To Store Distilled Water
Now that you know how to check the quality of your distilled water, what does it take to store your water correctly?
1. Avoid direct sunlight
It is best to store distilled water away from direct sunlight, especially if the water is in a plastic container. Sunlight will disintegrate the plastic and cause chemicals to leak into the water, making it unsafe to consume or use.
2. Use the right storage container
Your choice of storage container will make a big difference when it comes to preserving the quality of distilled water.
For larger quantities, we recommend storing in high-density polyethylene (HDPE) drums or tanks. Check that these containers are specifically food-grade quality to ensure that your water stays pure for longer.
The advantage of HDPE tanks is that they are not prone to rust, are impact resistant, keep the water cool, and protect water from light exposure.
If you only have small quantities of distilled water, it is best to store it in glass bottles. Unlike plastic bottles, glass will not disintegrate and release chemicals into the water.
3. Keep containers tightly sealed
Whether you store distilled water in tanks or small bottles, you should always keep the container tightly sealed. This keeps contaminants away and ensures that the water stays pure for use.
4. Store away from odorous materials
Distilled water, like other types of water, picks up surrounding smells. This will not necessarily affect the purity of the water or make it unsafe to use in your appliances but you definitely do not want to deal with water that smells like gasoline or paint.
To keep your distilled water tasting and smelling fresh, store it in a pantry away from items that have a strong odor such as paint or cleaning products.
5. Refrigerate after opening
The best location to store distilled water is in a cool, dark place. The refrigerator or pantry is a great choice. Just to be sure, refrigeration will not extend the water’s shelf life but storing the water away from direct sunlight is a sure way to keep it pure for longer.
The Risks Of Consuming Contaminated Distilled Water
Most people use distilled water in household appliances and in automobiles to avoid corrosion of metal parts.
There is nothing wrong with drinking distilled water but you should probably not do it for the long term. This water lacks important minerals such as magnesium, calcium, sodium. Not only does the water taste bland; it also will not provide you with the minerals your body really needs.
Like other types of water, drinking contaminated distilled water can have serious health consequences. According to the United States Environmental Protection Agency (EPA), drinking water with high amounts of chemical contaminants can lead to skin discoloration and problems of the nervous system. Consuming lower doses of chemically contaminated water over a long period can increase the risk of cancer.
Drinking distilled water that has been contaminated by pathogens can lead to symptoms such as diarrhea, headache, stomach pain, and fever. In severe cases, one may develop kidney failure.
If you notice any signs of ‘spoilage’ such as algae, cloudiness, sedimentation, or an off-taste or smell, be on the safe side and discard the water.
Can You Freeze Distilled Water?
You can freeze distilled water. The process of freezing distilled water is no different from that of freezing normal tap or purified water.
Some people also wonder whether distilled water freezes faster. Pure distilled water does not freeze any faster or slower than pure tap water. How fast water freezes depends on factors such as the presence of impurities, which slow down the freezing process, the temperature of the freezer, the temperature of the water, and the amount of water in the container.
Freezing distilled water is actually quite easy and is just the same as freezing ‘regular’ tap or bottled water. Here’s what you need to do:
- Pour distilled water into plastic bottles
- Place the bottles flat in the freezer
- Allow water to freeze for several hours
To defreeze, simply remove it from the freezer and place it in the fridge or on the countertop if you need warmer water.
Distilled water might be a bit different from normal water in that it does not contain minerals and other impurities but that is where the differences end.
The water will not go bad per se but if not properly packaged or stored, distilled water will become contaminated and unsafe to handle. Freeze, refrigerate or store distilled water in a pantry away from direct sunlight to keep your water fresher for longer.
3 thoughts on “Does Distilled Water Go Bad？How Long Does It Last?”
What is shelf life of distilled water if used to make nasal saline solution?
Distilled water. If it’s to clean a wound, then would it be contaminated if it’s been in a closed container in a dark pantry?
My husband bought 2 jugs of distilled water from the grocery store. They were the last 2 on the shelf (covid shortages). The bottles appear to be – for want of a better description – a bit swollen. The cap looks like it’s being sucked downward. I’m wondering if the water is OK to use and the misshapen bottle is just a fluke. I have seen this once before and the water appeared to be fine (we don’t consume it).