Q. I have kind of a weird question. I work outdoors during the summer, and I find that my water bottles get really hot and the water tastes gross. I have a thermal lunch bag, but it doesn’t seem to help much. There’s nowhere really to buy cold water bottles at my work sites, so I have bring them from home. Someone I know suggested that I freeze the water bottles the night before, so that the water will be cold all day. I know that water expands when it freezes, so I’m not sure if freezing a full water bottle would cause it to burst in the freezer. Also, I’ve heard that unsafe chemicals can leach into the water from plastic water bottles during freezing. I don’t really want to ingest unsafe chemicals. Can you freeze water bottles?
A. You’re right that water expands upon freezing. Still, you can freeze water bottles. I would recommend letting an inch or two of water out first before resealing the bottle and placing it in the freezer. This would ensure there is enough room for expansion during freezing without worrying the lid will pop off!
There are also many people who believe it is unsafe to freeze water bottles because of the chemicals in the plastic, but there is no current scientific evidence at the time of writing to support that claim. Plastics are used to freeze foods all the time in the form or freezer bags and other hard sided plastic containers, and most people do not believe them to be unsafe for use. Water bottles are similar. To freeze water bottles, remove a bit of liquid to allow for expansion, reseal tightly, and place in the freezer until you need it.
You mentioned that you want to use the water bottles during the day at work. In that case, simply removing the water bottle from the freezer in the morning might result in you waiting a long time for the block of ice to thaw. I recommend freezing a half-full water bottle. Then, in the morning before work, removing the bottle from the freezer and filling it with water. This way, the ice keeps the water cold, and the rest of the bottle will thaw gradually, allowing you to enjoy ice cold water all day.