Carrying along water is essential for hot weather walks. But what if you find your water tasting funky when using your reusable water bottle or hydration pack?
Keeping your water bottle clean is the key to preventing bad taste. Bacteria and fungus can grow in wet bottles, and they especially love and leftover drinks that contain sugar or juice. If you use your water bottle for sports drink, you must wash it immediately after use with warm water and soap, and allow it to dry out completely before replacing the cap.
This is still the best policy if you just use it for water. Handwash with liquid dish soap and warm water, and allow it to air dry.
If you have been lazy and discover it days later with a growing colony of mold and a vile swill of cloudy bacteria-laden fluid, then you will likely need to use bleach or a denture-cleaning tablet to get it clean again. Use a cap-ful of bleach and fill the bottle with water and allow this to sit for at least an hour, or overnight. Then rinse and scrub with hot water and dish soap. The drawback here is that the bleach taste can take awhile to get rid of, so it is best to avoid letting your bottle get into that condition in the first place.
For fewer problems, use any of the methods I have in Ways to Clean and Deodorize Your Hydration Pack.
Another option instead of chlorine bleach to clean the bottle or pack is a tablespoon of baking soda and some 3% hydrogen peroxide. The baking soda will activate the peroxide and get rid of the funk, and it is odorless and tasteless and therefore much easier to rinse out than chlorine bleach.