Quick Answer
Generally, it is safe to use distilled water past its expiration date, as long as it has been properly stored in a sealed container. The expiration date on distilled water mainly refers to taste and quality rather than safety. As distilled water does not contain nutrients that can spoil, bacteria cannot grow in it. However, if the container was opened or contaminated, expired distilled water may pose health risks and should not be used.
Does Distilled Water Expire?
Distilled water has an expiration date printed on its packaging, typically 2 years from the production date. However, this expiration date does not indicate that the water will become unsafe to consume, but rather that the quality and taste may start to degrade.
Distilled water is produced by boiling water and condensing the steam to remove impurities like minerals, chemicals, and microbes. This process kills bacteria and limits contaminants that could cause the water to expire. An unopened bottle of distilled water can be stored indefinitely.
Once opened, distilled water should be used within 6 months. The expiration date is meant to indicate the point at which the quality of the distilled water, in terms of taste and mineral content, may start to change.
Why Does Distilled Water Have an Expiration Date?
There are a few reasons why distilled water comes with an expiration date:
- Taste – Over time, exposure to air and plastic from the container can cause distilled water to develop a stale, flat taste.
- Contamination – Once opened, distilled water is more susceptible to airborne contaminants and microbes that can start to degrade quality.
- Plastic Leaching – Plastic packaging may start to breakdown and leach compounds into the water over the expiration date.
- Manufacturer Recommendation – The expiration date is the manufacturer’s recommendation for best quality, not necessarily an indicator of when the water becomes unsafe to drink.
So while expired distilled water won’t make you sick if you drink it, the taste and quality may progressively worsen past the expiration date.
Is it Safe to Drink Expired Distilled Water?
Yes, drinking expired distilled water is generally safe. Since distilled water is purified through the distillation process, there are no bacteria, minerals or other contaminants present in the water that could spoil or expire.
As long as the unopened, sealed distilled water container remains properly stored away from direct sunlight and temperature fluctuations, the water inside remains safe to consume indefinitely. There is no risk of illness from drinking dated distilled water.
Precautions with Expired Distilled Water
While drinking expired distilled water is safe, some precautions should be taken:
- Check for leaks or damage to the container that could have allowed contamination.
- Give the water a smell and visual check – it should not have an odor or be discolored.
- Check for sediment at the bottom of the container that could indicate contamination.
- Test the pH of the water if possible – it should be close to neutral pH of 7.
If there are any signs of damage to the container or abnormalities in the water’s appearance, odor or pH, it is best to discard the water instead of risking contamination.
Risks of Drinking Contaminated Distilled Water
While uncommon in unopened containers stored properly, contamination is possible:
- Bacterial growth – Without minerals and nutrients, bacteria generally cannot multiply in distilled water. But certain bacteria like Legionella can occasionally survive.
- Chemical leaching – Plastic packaging may leach bisphenol A (BPA), phthalates and other chemicals over time into the water.
- Metals and minerals – Improper storage containers could leach lead, copper or unwanted minerals into expired distilled water.
Drinking contaminated expired distilled water could potentially cause temporary symptoms like:
- Nausea, vomiting or diarrhea
- Headache or dizziness
- Abdominal cramps
However, serious illness is very rare from drinking expired distilled water that has been properly sealed and stored.
How to Store Distilled Water Properly
To maximize the shelf life and safety of distilled water, follow these proper storage guidelines:
- Use the original container – Do not transfer to a temporary container, as this increases contamination risk.
- Seal completely after opening – screw caps on tightly or use sealing tape.
- Keep in a cool, dark place – Store away from heat sources and sunlight to prevent plastic degradation.
- Avoid extreme temperatures – Prevent freezing or temperature fluctuations to preserve taste.
- Store upright – Keep the container vertical to avoid leakage.
- Use clean storage containers – Wash containers with hot water and dish soap before refilling.
- Limit transfer between containers – Each transfer is an opportunity for contamination.
- Check seals over time – Ensure caps and containers remain properly sealed during storage.
- Watch expiration dates – For best quality, use unopened containers before expiration date.
Recommended Distilled Water Storage Containers
The best containers for storing distilled water include:
- Original container – This is sterile and designed for optimal water preservation
- PET plastic – Durable, shatterproof, easy-to-seal jugs or bottles
- Glass – Non-leaching into water, but fragile and heavy
- Stainless steel – Inert and long-lasting, but more expensive and prone to dents
Containers to avoid:
- PVC plastic – Can leach phthalates into water over time
- Copper – Leaches copper ions that change taste and quality
- Galvanized metal – Leaches dangerous zinc and lead into water
Uses for Expired Distilled Water
If you have distilled water that is past the expiration date, there are many safe uses aside from drinking:
Cleaning and household uses
- Cleaning windows and mirrors
- Wiping down counters
- Cleaning out appliances like coffee makers
- Cleaning jewelry
- Adding to steam irons
- Filling humidifiers
Personal hygiene uses
- Brushing teeth
- Using as mouthwash
- Filling water picks
- Nasal rinsing
- Moistening contacts
Pet and plants
- Filling pet water bowls
- Watering houseplants
- Topping off fish tanks
- Misting reptile tanks
Automotive uses
- Filling radiators and batteries
- Cleaning car windows
- Rinsing car mats
The purity of distilled water makes it ideal for applications where mineral-free, contaminant-free water is required. While the expiration date indicates the water may not be tasty, it remains safe for alternative purposes.
Does Distilled Water Go Bad Once Opened?
Once opened, distilled water can go bad eventually if it becomes contaminated, but this takes longer than with tap water. An opened bottle of distilled water will generally stay fresh and safe to drink for up to 6 months if properly stored and re-sealed.
Signs that opened distilled water has gone bad include:
- Cloudiness or sediment
- Strange odors
- Sour or unpleasant taste
- Unusual colors or darkening
- Algae or microbial growth in the bottle
If opened distilled water develops any foul characteristics, it is best to discard it instead of trying to determine if it’s safe or not.
How to Extend Life of Opened Distilled Water
To maximize the shelf life of distilled water after opening, follow these guidelines:
- Re-seal the container tightly after each use
- Store away from sunlight and heat sources
- Refrigerate after opening for cool storage
- Avoid transferring back and forth between containers
- Use clean drinking glasses to access water
- Keep appliance reservoirs clean that use distilled water
- Watch for any changes in smell, taste or appearance
Safety Tips for Opened Distilled Water
- When in doubt, throw it out. Don’t take risks with contaminated water.
- Never store distilled water in lead or copper containers which can leach metals.
- If it smells bad, tastes off or you see sediment – do not drink it.
- Monitor water closely for any scum, floaties or buildup in the container.
- Always wash hands prior to handling distilled water containers.
With proper precautions, opened distilled water can remain fresh for up to 6 months after which it’s best to discard and open a new container.
Signs Distilled Water Has Spoiled
On very rare occasions, distilled water can become contaminated and spoiled if not properly stored long-term. Here are the signs that your distilled water has spoiled and should be discarded:
- Appearance Changes – Cloudiness, sediment, particles or film on the water’s surface indicate contamination.
- Odor – A foul sulfur smell, rotten egg smell or any pungent odor means the water is spoiled.
- Flavor – An off taste that is salty, bitter, metallic or soapy points to the water being contaminated.
- Color – Any changes from clear to a yellow, brown or greenish tinge signal the water is no longer fresh.
- Algae Growth – Visible green, red or black growth or slimy texture means the water harbors microbes.
- pH Change – If a pH test strip indicates the water is no longer neutral pH of around 7, it may be compromised.
- Container Damage – Any leaks, cracks or damage to the distilled water container integrity can allow contamination.
While rare in sealed containers stored properly, if any signs of spoilage appear do not drink the water. Odor, taste and sight are typically the best indicators the distilled water has gone bad.
Distilled vs. Purified vs. Spring Water
Understanding the different types of bottled waters can help determine if expiration dates need to be strictly followed:
Distilled Water
- Produced by distillation – water is boiled and steam condensed
- Removes ALL impurities including minerals
- Neutral pH and taste
- No minerals means nothing to “expire”
- Long shelf life if sealed
Purified Water
- Processed to remove chemicals/toxins through filters
- Contains beneficial minerals
- Can have slightly mineralized taste
- Minerals may grow bacteria over time
- Use within 6-9 months of expiration
Spring Water
- Sourced from natural springs
- Contains minerals and natural contaminants
- Has distinct mineral taste
- Can grow mold, algae and bacteria
- Use within 1-2 months of expiration
Due to the lack of minerals and contaminants, unopened distilled water generally has the longest shelf life before expiry compared to other bottled waters.
Frequently Asked Questions
Is it bad to drink expired distilled water?
Generally, no – Expired distilled water in properly sealed containers is still safe to drink since it does not spoil or grow bacteria without nutrients. However, the taste and quality may deteriorate so it is not recommended to drink.
Does unopened distilled water ever expire?
Technically no – If stored properly, unopened distilled water can last indefinitely without going bad or becoming unsafe to drink. The 2 year expiration date is mainly for best taste and quality rather than safety.
Can old distilled water make you sick?
No, drinking expired distilled water will not make you sick or cause health issues. The only risk would be from improper storage leading to contamination, which is rare for sealed water bottles stored correctly.
Why does my distilled water smell bad after expiration?
A foul odor in expired distilled water likely means the bottle has been contaminated with bacteria from improper storage or repeated opening. An opened bottle should not be consumed if the smell is off.
Is it better to drink purified or distilled water after expiration?
Distilled water will remain safer and last longer after expiration compared to purified water. Distillation removes all contaminants while purified water still contains minerals that can grow bacteria over time.
Conclusion
Checking expiration dates on distilled water bottles is still advised for best quality and taste. However, thanks to the distillation process, unopened distilled water remains safe to drink even years past its expiration date if it has been properly sealed and stored.
Once opened, distilled water is more susceptible to contamination and should be consumed or re-purposed within 6 months. But if you are ever uncertain about the safety of expired distilled water, it is always best not to take risks and discard it.
