how to clean hydro flask

How To Clean Hydro Flask

Staying hydrated is essential for our health, and Hydro Flask water bottles make it convenient and stylish to keep water within reach at all times.

The insulated bottles keep your drinks at the perfect temperature, and their robust design makes them perfect for outdoor activities or everyday use. However, to ensure your Hydro Flask’s longevity and maintain its effectiveness, regular cleaning is a must.

This comprehensive guide will walk you through how to clean your Hydro Flask correctly.

What You Will Need

For cleaning your Hydro Flask, you will need:

  • Warm soapy water
  • A long brush (like the Hydro Flask Bottle Brush)
  • Baking soda
  • White vinegar
  • Lemon juice
  • A kettle for boiling water

Step One: Rinse It Out

Begin your cleaning process by rinsing out the Hydro Flask with warm water. This initial step will help remove any residue from your last beverage.

Step Two: Use Soap and Water

Fill your Hydro Flask with warm soapy water. Using a Hydro Flask Bottle Brush or a similar long brush, thoroughly scrub the inner walls of your water bottle. Pay special attention to the bottom as particles often settle there. Rinse well and let dry completely.

Step Three: Use Baking Soda

If your Hydro Flask has a persistent smell or stain, a baking soda paste can be very effective. Mix a few tablespoons of baking soda with just enough water to form a paste. Apply the paste to the interior of the Hydro Flask and scrub with your bottle brush. The abrasive properties of baking soda help remove stubborn stains and deodorize your flask.

Step Four: Use Vinegar

White vinegar is an excellent cleaning agent. Pour a small amount of vinegar into your Hydro Flask and shake it around, ensuring it reaches all interior surfaces. Let the vinegar sit for about 5 minutes and then rinse thoroughly. Vinegar not only cleanses but also disinfects your water bottle.

Step Five: Use Lemon Juice

Lemon juice is another natural cleaning solution. The acid in the lemon juice breaks down any residue, and its natural fragrance leaves your Hydro Flask smelling fresh. Fill one quarter of your Hydro Flask with lemon juice and the rest with warm water. Allow this solution to sit for a few hours, then rinse and dry.

Step Six: Use boiling Water

Pour boiling water into your Hydro Flask to sterilize it thoroughly. Let the hot water sit in the flask for several minutes before pouring it out. Be careful while handling the flask with boiling water to avoid burns.

Are you supposed to wash your Hydro Flask?

Yes, it’s essential to clean your Hydro Flask regularly to prevent bacteria and mold growth. Regular cleaning also helps remove any lingering odors or tastes.

How often should you wash your Hydro Flask?

The frequency of cleaning your Hydro Flask depends on how often you use it. If you use your Hydro Flask daily, it’s best to clean it every day. If you’re using it less frequently, a good rule of thumb is to clean it after every use.

Cleaning Hydro Flask Straw Lid

To clean the Hydro Flask straw lid, disassemble the lid components and soak them in warm soapy water. Use a small brush to clean the valve well and straw. Rinse well and let them dry completely before reassembling.

Cleaning Flex Cap

The flex cap can be cleaned similarly to the straw lid. Disassemble, if possible, soak in warm soapy water, scrub with a brush, rinse, and let dry.

How do you clean a smelly Hydro Flask?

Over time, you might notice a smell developing in your Hydro Flask. This usually results from bacteria buildup. Use the methods outlined above—soap and water, baking soda, vinegar, or lemon juice—to eliminate the odor. For particularly stubborn smells, a combination of methods may be necessary. Always ensure that the bottle is thoroughly dried after cleaning to prevent any residual moisture from encouraging bacterial growth.

Why does my Hydro Flask smell even after washing?

If your Hydro Flask still smells even after washing, there may be bacteria trapped in hard-to-reach areas. These spots might include the cap, especially if it has a straw or spout, or the very bottom of the flask. Using a specialized cleaning brush, such as the Hydro Flask Bottle Brush, can help reach these difficult areas. Moreover, make sure you dry your flask and its components completely, as moisture can lead to bacterial growth and foul smells.

Avoiding Certain Food and Drink in Hydro Flask

While your Hydro Flask is perfect for keeping drinks at their ideal temperature, some beverages may stain or leave lingering smells. These include coffee, tea, juice, and alcoholic beverages. Additionally, dairy products or soup can leave residues that are difficult to remove and promote bacterial growth. To prevent any stains or smells, rinse your Hydro Flask with warm water after each use.

What are the black flakes in my Hydro Flask?

If you find black flakes in your Hydro Flask, it’s likely a sign of mold growth. Mold can occur if your Hydro Flask isn’t cleaned regularly or left damp. If you discover mold, clean your flask thoroughly with baking soda, vinegar, or boiling water. If the mold persists, you may need to replace your Hydro Flask.

What is the black stuff in my Hydro Flask lid?

Similar to the black flakes in your Hydro Flask, black stuff in the lid can indicate mold or mildew growth. This commonly occurs in areas that are not cleaned thoroughly, such as the inside of the cap or straw. Make sure to disassemble and clean all parts of your lid to prevent this problem.

Using Hydro Flask Accessories for Easy Cleaning

Hydro Flask offers several cleaning accessories, such as the Hydro Flask Bottle Brush, which can reach deep into your flask and clean difficult-to-reach spots. It’s designed specifically for Hydro Flask bottles, so it can be particularly effective.

Tips to Keep Hydro Flask Clean and Fresh

Here are some tips to keep your Hydro Flask clean and fresh:

  • Rinse your Hydro Flask with warm water after each use.
  • Regularly deep clean your flask with soap and water, baking soda, vinegar, or lemon juice.
  • Ensure you clean all components, including lids and straws.
  • Always let your flask dry completely before storing it.
  • Avoid leaving liquids in the flask for long periods, as they can lead to bacterial growth and odors.
  • Do not store your Hydro Flask while it’s damp or sealed with liquid inside.


A clean Hydro Flask ensures that every sip is as fresh and refreshing as possible.

With these cleaning instructions, you can easily maintain your Hydro Flask, preserve its durability, and enjoy your beverages at their best.

Remember, regular care and handwashing are key to keeping your Hydro Flask in its optimal condition.


  1. Can I clean my Hydro Flask in the dishwasher?

    • Only the stainless-steel Hydro Flask bottles and some lids (like the Flex Cap, Wide Flat Cap, and Standard Mouth Loop Cap) are dishwasher safe. Other components, like the sports cap or flex straw cap, should be hand washed.
  2. Can I use bleach to clean my Hydro Flask?

    • It’s not recommended to use bleach or harsh chemicals as they can damage the flask’s insulation property and leave a residue that can affect the taste of your beverages.
  3. Is it normal for my Hydro Flask to have a slight odor?

    • A slight odor can develop if your Hydro Flask isn’t cleaned regularly or thoroughly. Follow the cleaning methods in this guide to remove any odors and prevent them from reoccurring.
  4. What should I do if my Hydro Flask has mold?

    • If you spot mold, clean your Hydro Flask thoroughly with baking soda, vinegar, or boiling water. If the mold persists, it might be time to replace your Hydro Flask.
  5. How do I maintain the vacuum insulation of my Hydro Flask?

    • Avoid using bleach or harsh cleaning agents. Regular handwashing, using mild dish soap, is recommended. Also, avoid extreme temperature changes, like moving from a freezer to boiling water, which can damage the vacuum seal.

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