Learn how to do anything: How to Clean a Hydro Flask

Cleaning your Hydro Flask is super fast and easy. The main thing you will want to invest in is a bottle brush. You can use a brush specifically made for the Hydro Flask, or a standard baby bottle brush will do the trick. Daily cleanings with soap and hot water are recommended to maintain your Hydro Flask, but occasionally you will need to do a deeper cleaning to get rid of bacteria and stubborn stains.

EditSteps

EditWashing with Dish Soap

Disassemble your Hydro Flask to clean it. Unscrew the lid and remove it from the bottle. If your Hydro Flask has a straw, separate the straw from the lid.
- It’s important that you take your Hydro Flask apart before cleaning it. In order to get a good cleaning, you’ll need to wash all of the components, not just the outside of the bottle and the spout.
Wash your Hydro Flask pieces separately with hot, soapy water. Use a clean dishcloth or sponge to wash the outside of your bottle, all models of Hydro Flask lids, and the outside of the straws. Clean the inside of your bottle with a bottle brush.
- A sponge or rag won’t be able to reach the bottom of your bottle, so you’ll definitely want to use some type of long brush. A bottle brush from the baby section of your local department store would perfectly.
- Do not soak your lid. Submerging the lid for an extended period of time can trap water inside of it.^[1]
- Pay special attention to the drinking spouts since this is where bacteria likes to collect. If you have one, use a small bottle brush or nipple brush to help clean these small spaces.^[2]
- If you have pipe cleaners, use one to clean the inside of the straw. Simply insert the pipe cleaner into one end of the straw, and firmly move it up and down along the insides to remove any buildup.^[3]
Rinse all of your Hydro Flask pieces thoroughly. It’s important to remove all traces of the soap. Leaving soap in any of the pieces of your Hydro Flask can lead to a build up of residue. This typically won’t hurt you, but it can affect the taste of your water.^[4]
- Run tap water over the top of the lid, then flip the lid over to allow the water to run through the underneath side as well. Slowly rotate the lid under the water to make sure it is completely rinsed off.
- Hold one opening end of the straw under the running tap water to rinse it out. Allow the water to flow through the straw for about 10 seconds, or until the water runs clear.
Use a dishwasher to wash a flip lid or a wide straw lid. The Hydro Flip and Wide Straw models are the only 2 lids that can be washed in the dishwasher. Lids to all other Hydro Flask models should be washed by hand.^[5]
- Note that frequent washing in the dishwasher can cause extra wear and tear on these lids. If it’s possible, still wash these lids by hand during regular cleanings, and save the dishwasher for occasional deep cleanings.^[6]
Air-dry all of the pieces until they are completely dry. The lid and straw may take longer to dry than the bottle because of the threading, enclosed spaces, and small nooks. To avoid a build up of germs and bacteria, make sure all of the pieces are allowed to air dry completely before reusing them.^[7]
- Thoroughly drying your flask is the most important step, so don’t skip it!^[8]
- Try washing your Hydro Flask in the evening, that way it can dry overnight and will be ready to use the next morning.

EditUsing Vinegar to Remove Bacteria

Pour ½ cup (118 ml) of distilled white vinegar into your Hydro Flask. Gently swirl the vinegar around in a circular motion to coat the inside of your flask. Allow the vinegar to sit for 5 minutes.
- Alternatively, fill your Hydro Flask about ⅕ of the way with vinegar and the rest of the way with water. Allow the solution to sit overnight.^[9]
- Using distilled white vinegar to clean your Hydro Flask is the best option for effective cleaning. Using other chemicals like bleach or chlorine can damage the outside of the bottle and cause the stainless steel to rust.^[10]
Use a bottle brush to scrub hard-to-reach places in your flask. A bottle brush will be the most effective in cleaning the inside of your bottle. It can reach the difficult places and it has a little more friction than a sponge or a dishcloth.
- Firmly press the bristles along the inside walls of the flask. Be sure to get all the way down to the bottom of the bottle, and underneath the ledge at the top of the flask.
Rinse your Hydro Flask thoroughly with warm water. Run warm tap water into your flask. Swirl the water around a few times and then pour the water out. You may need to do this 2 or 3 times to make sure it completely rinsed.
Allow your Hydro Flask to air dry upside down. Use a dish drying rack, or prop the bottle up at an angle against the side of the sink. Air needs to be able to circulate in order to prevent bacteria from growing.^[11]
- Make sure your Hydro Flask is ready to use by washing it in the evening and allowing it to dry overnight.

EditRemoving Tough Stains with Baking Soda

Mix 2-3 tbsp (30-44mL) of baking soda with warm water to form a paste. Put the baking soda in a small a bowl and stir in a little bit of water. The consistency should be a thick paste.^[12]
- If the mixture is too thick, add a little more water to thin it out. If you put too much water and the mixture is too thin, add a little more baking soda to thicken it.
Scrub the inside of your Hydro Flask with the paste. Dip a bottle brush into the paste, making sure to coat the bristles heavily. Use the brush to scrub the inside of your flask. Target areas that are badly stained by using small, circular motions.
- Repeat this step as needed. It may take a few times to completely remove the stain, so don’t worry if the stain doesn’t come out on the first go.
Rinse your Hydro Flask thoroughly with warm water. Fill your flask with warm tap water. Use the bottle brush along the insides of the flask to loosen up the baking soda paste. Swirl the water around the bottle a few times and then pour it out.
- Try filling the bottle up about halfway with water, putting on the lid, and gently shaking the bottle up and down. Pour the water out and run fresh water through the bottle. The agitation will help clear out excess residue.
- Once there is no baking soda residue remaining on the inside of the flask, continue to run the warm water into the flask, swirl it around, then pour it out. Repeat this step 2 or 3 times, or until the water runs clear.
Dry your Hydro Flask by allowing it to sit upside down. Place the bottle in a dish drying rack, or try propping it an angle against your kitchen wall or the side of the sink. Just make sure it has proper air circulation to prevent bacteria from growing.^[13]
- To help with timing, try washing your Hydro Flask in the evening to allow it to dry overnight and be ready to use the next day.