Sport bottles are often shaped with lots of curves and crannies where liquids can sit and dry. This can cause your sport bottle to not only have an odour, but to not come clean with a normal dishwasher washing, and they can then grow mould and other bacteria. Cleaning sport bottles requires a certain routine to make sure they are completely clean inside and out.
Fill the bottle with hot water and a few drops of dishwashing detergent. Place the cap on and shake vigorously.
Open the cap and squeeze the water and detergent out through the valve. This will help make sure that your cap and nozzle are clean as well. Use a washcloth to clean the outside of the bottle with hot water and detergent.
Pour 2 tbsp of baking soda into the bottle, then add 1/2 cup of vinegar. This creates a fizzing reaction that should fill the bottle. Allow this to sit for about five minutes. Vinegar kills mould and mildew germs and baking soda will aid in cleaning and removing odours.
Use a bottle brush to scrub the inside of the sport bottle with the vinegar mixture. Make sure to get all around the neck and grooves of the bottle. Place the lid on and squeeze the vinegar and baking soda through the nozzle as well.
Rinse thoroughly with hot water and place the bottle on a clean towel to dry completely.