Can distilled water go bad?
Matthew Wilson
Updated on March 01, 2026
Unopened bottled distilled water from a store lasts basically forever. But stash it away from direct sunlight. And once it’s opened, be sure to close it up well after use.
Can bacteria grow in distilled water?
Many microorganisms (“oligotrophs”) grow in distilled water: Pseudomonas spp., Caulobacter spp., Hyphomicrobium spp., Arthrobacter spp., Seliberia spp., Bactoderma alba, Corynebacterium spp., Amycolata (Nocardia) autotrophica, Mycobacterium spp., yeasts, and Chlorella spp.
How long can distilled water be stored after opening?
Distilled Water Shelf Life
| Refrigerated | Pantry | |
|---|---|---|
| Opened bottle of distilled water | 9-12 months | 3 days-1 week |
| Unopened bottle of distilled water | 2+ years | 2+ years |
Can distilled water go bad in heat?
Storage: Distilled water should be stored in a cool dry location to optimize shelf life. When well maintained, the bottled water can last years on the shelf. It is not a good idea to store distilled water in extreme heat. Heat causes plastic chemicals to seep into the water at an increased rate.
Is distilled water in plastic jugs safe?
We recommend that you store it in a glass container. Plastic containers can cause the distilled water to become contaminated as it will leach the chemicals from the plastic. Glass has been proven to be the best option as it will have minimal effect on the water over time.
Can I use expired distilled water in my CPAP machine?
Can You Use Expired Distilled Water In A CPAP Machine? As long as it has been stored properly and you do not detect any signs of contamination, distilled water past its expiration date can work just fine in a CPAP machine.
Will distilled water get moldy?
Distilled Water is Healthy It is also healthier as it will not release mold or mineral dust into the air.
Does distilled water cause mold?
While you can experience pink mold even when using distilled water, it is most common to experience pink mold and bacteria growth when you are using tap water. This is again because of the mineral content of your tap water. In order for you to avoid frequent mold buildup, you can use distilled water instead.
Do I need to refrigerate distilled water after opening?
Does distilled water need to be refrigerated after opening? No. After opening, distilled water does not need to be refrigerated. But, of course, you can do it, just treat it the same way as any other bottled water.
Do you have to refrigerate distilled water once opened?
Do I need to clean my humidifier if I use distilled water?
If you are using distilled water, you will not have to clean your humidifier as often. Also, your humidifier is much less likely to develop mold or odors. It is also much healthier as there is no hard mineral build up or bacteria growth.
Do you have to clean humidifier if I use distilled water?
The water you use to fill your tank could also cause issues. Both the CPSC and the EPA recommend filling your humidifier with distilled water—not tap—to keep potentially harmful microorganisms out of the air you breathe.
Is drinking too much distilled water bad for You?
Usually, the answer is yes, you can drink distilled water. If drinking water is purified using distillation, the resulting water is cleaner and more pure than before. The water is safe to drink. The disadvantage to drinking this water is that most of the natural minerals in the water are gone.
What are the side effects of distilled water?
Too much water: This can cause water intoxication, severe changes in electolytes especially sodium and lead to edema, seizures, brain damage and death.
Does distilled water go bad?
In general, normal water rarely goes bad on its own, however, packaging and the outside environment can have a lasting impact on how long your water lasts and the quality thereof. Distilled water goes through a purification process of distillation, leaving water that is free of impurities and unwanted minerals.