Clean a reusable water bottle by washing it with hot water, dish soap and a long bottle brush, scrubbing the bottom and the threads at the neck. Then take the lid apart: pull out the straw and the silicone gasket and wash each piece separately. Rinse well and let everything air dry before you put it back together.
Do it daily if you use the bottle daily. That sounds like a lot until you realize it takes two minutes, and that skipping it is how you end up with the black spots in the lid seal that nobody wants to scrub.
How often should you wash a reusable water bottle?#
| What was in it |
When to wash |
| Plain water, used every day |
Daily with soap. Take the lid apart at least once a week. |
| Juice, smoothies, sports drinks, coffee, tea, milk |
The same day you finish it |
| Anything, left sitting for a few days |
Before you use it again |
| Bottle smells, feels slimy, or has visible spots |
Now, with a deep clean |
The bottle body is the easy part. The lid is where problems start, because water sits in the straw, the valve and the groove behind the gasket long after the bottle looks empty.
How to wash a water bottle, step by step#
- Empty the bottle. Don't keep topping up yesterday's water.
- Take the lid apart. Pull out the straw, pop out the silicone gasket (a fingernail or the handle of a teaspoon gets under it without nicking it), and remove any removable mouthpiece. Lay the pieces on a clean towel in order, or snap a photo, so reassembly isn't a puzzle.
- Fill the bottle partway with hot water and a drop of dish soap. Scrub the inside with a bottle brush, paying attention to the bottom corner and the threads at the neck.
- Wash the lid pieces in the same soapy water. Push a straw brush all the way through the straw from both ends. Use a small detail brush on the gasket groove and the mouthpiece channel.
- Rinse every part until there's no soap smell or film left.
- Leave the pieces apart to dry, with the bottle upside down on a rack or open side up somewhere airy. Don't seal a wet lid onto a wet bottle.
- Refit the gasket so it sits flat in its groove, put everything back together and check for leaks over the sink with plain water.
Don't pry apart a valve that isn't designed to come out. If you can't reach inside a part and it's grubby, replace that part.
Deep cleaning a straw lid#
Hydro Flask's straw lid cleaning guide gives a good deep-clean method for when soap and a brush aren't enough. Mix half a cup of hydrogen peroxide with two tablespoons of baking soda, soak the straw parts in it for 30 minutes, run a pipe cleaner through the inside, then wash with warm soapy water and rinse. Let everything air dry completely before you put the lid back together.
The same guide suggests rinsing the straw each time you refill, which keeps deep cleans rare. It also says to skip cleansers containing bleach or chlorine, to protect the lid. That's a reasonable rule for most plastic and silicone lids unless your bottle's instructions say otherwise.
Can you put a water bottle in the dishwasher?#
Sometimes, and the answer can change between versions of the same bottle. Hydro Flask's dishwasher guidance says its current bottles are dishwasher safe, but older ones, marked with a trademark symbol next to the logo, should be washed by hand. Its straw lid guide says most straw lids can go in, with the straw on the top rack. Other brands differ, so check the bottle and the lid separately.
If the manufacturer says hand wash, believe it. Dishwasher heat can warp seals and lids, and a lid that no longer seals properly leaks into your bag. The dishwasher also won't push water through a narrow straw, so straws need a brush either way.
How to get rid of a smell or mold in a water bottle#
A musty smell usually means the lid isn't drying properly between uses. Take it apart, deep clean it with the soak above, and leave every piece apart overnight to dry.
Black or pink spots in a silicone gasket or a soft bite valve mean mold or bacteria have settled in. Scrub the gasket with a small brush and soapy water. If the spots won't come off, or the silicone is stained, cracked or permanently cloudy, replace the part. Many bottle brands sell spare gaskets, straws and bite valves, and they're cheap compared with a new bottle.
Common mistakes#
- Washing the bottle and leaving the lid assembled. The gasket groove never gets touched.
- Using the same old kitchen sponge for the inside. A dirty sponge spreads more than it removes, so it's worth knowing how often to replace kitchen sponges.
- Storing the bottle closed and damp in a bag or a cupboard.
- Leaving sweet drinks in it overnight.
If the bottle is spotless and your water still tastes off, the problem may be upstream. A refrigerator water filter that's past its date is one thing to rule out.
A weekly ChoreLists.com reminder to take the lid apart is a good backstop for the days you rush the daily wash.