Hydro Flask water bottles have become incredibly popular in recent years for their ability to keep beverages hot or cold for hours. Made out of stainless steel and fitted with a special TempShield insulation layer, Hydro Flasks are virtually indestructible and can withstand daily wear and tear.
However, even the best water bottles need to be cleaned regularly to keep them fresh and prevent the buildup of bacteria, mold, and odors. Cleaning your Hydro Flask properly ensures your water always tastes great and the bottle remains in perfect condition for years of reliable use.
In this comprehensive guide, we’ll provide tips on how to clean a Hydro Flask water bottle using common household items. We’ll cover how to clean the interior and exterior, how to remove stubborn stains and smells, and the best cleaning practices to make your Hydro Flask last.
Supplies Needed for Cleaning a Hydro Flask
Cleaning your Hydro Flask doesn’t require much. In most cases, all you need are some common household items. Here are the recommended supplies:
- Mild dish soap
- Bottle brush
- Baking soda
- White vinegar
- Fresh water
- Microfiber cloth
- Toothbrush (optional)
- Lemon juice (optional)
Dish soap and water should be your go-to cleaning solution. The soap helps cut through grease and grime, while the water rinses it away.
A bottle brush with sturdy, close-set bristles allows you to thoroughly scrub the inside of the Hydro Flask. Choose one with a long handle so you can easily reach the bottom.
Baking soda is mildly abrasive so it can help remove stubborn gunk. White vinegar kills bacteria and neutralizes tough odors. Lemon juice also cuts through funky smells.
Microfiber cloths and toothbrushes are good for scrubbing the threads, lid, carry loop, and other narrow crevices. Start your cleaning with this basic toolkit before moving onto other methods for extremely dirty bottles.
Step-by-Step Guide to Cleaning the Inside of a Hydro Flask
Follow these steps to clean the interior of your Hydro Flask:
1. Rinse With Warm Water
The first step is to rinse out the bottle with warm water. This will help loosen and wash away any loose dirt or residue.
Remove the lid and turn the bottle upside down over the sink. Let warm water run through the bottle for 30 seconds to a minute.
Give the bottle a few good shakes while the water is running to dislodge stuck-on grime.
2. Wash With Dish Soap
Next, it’s time to break out the dish soap. Add a few drops of mild, unscented soap to the bottle.
Use an amount about the size of a quarter. Too much soap will make the bottle hard to rinse.
Add enough warm water so the bottle is about 1/3 full when capped.
Place your hand over the mouth of the bottle and shake vigorously for 30 seconds or more to create suds. The motion will cause the soapy water to reach every spot.
Make sure to also remove the lid and wash it separately using the same soapy water. Scrub the rubber gasket as well.
3. Scrub With Bottle Brush
Now comes the muscle. Insert your bottle brush until it reaches the bottom of the Hydro Flask.
Twist and scrub the brush all around the interior, focusing on areas you see gunk. The bristles will remove all traces of dirt and bacteria buildup.
Be sure to get the threads around the rim. These can harbor mold if not cleaned properly.
When you’re done scrubbing, remove the brush and rinse it well since it will have collected residue.
4. Rinse Thoroughly
After scrubbing the inside with soap, it’s critical to rinse very thoroughly. You want to completely remove all soap and debris.
Fill the Hydro Flask to about 1/3 full with fresh, clean water. Cap it and shake vigorously again. The rinse water will become dirty.
Keep rinsing and shaking until the water comes out clear. You may need to repeat this several times.
Turn the bottle upside down and rinse the threads around the opening to remove any lingering soap bubbles.
5. Allow to Air Dry
When the inside is squeaky clean, place the bottle upside down in the dish rack or on a drying mat.
This allows all remaining water droplets to drain out so no moisture gets trapped inside.
Remove the lid and allow that to dry fully as well.
Do not use a towel to dry the inside of the bottle, as this can transfer bacteria. Air drying prevents any mildew smells.
And that’s it! Following these basic cleaning steps allows you to thoroughly clean the inside of your Hydro Flask.
Deep Cleaning a Smelly or Moldy Hydro Flask
If your Hydro Flask has developed stubborn smells or you see black spots of mold, you may need to do a deep cleaning.
Here are some tips for eliminating tough odors and removing mold growth:
Wash With Baking Soda
Baking soda is mildly abrasive so it can scrub away residues that cause odors. The soda also naturally deodorizes.
Add 1-2 tablespoons of baking soda to your Hydro Flask along with a small amount of water. Swirl the mixture around to scour the interior walls.
You can also use a bottle brush to help distribute the baking soda. Let it sit for 5-10 minutes before rinsing thoroughly.
For extra cleaning power, do this baking soda scrub after first washing with dish soap.
Sanitize With White Vinegar
White vinegar is a natural antibacterial that can kill mold and neutralize difficult smells.
Fill your bottle 1/4 full of undiluted white vinegar. Let it soak overnight (8 hours or more).
In the morning, dump out the vinegar and rinse several times with fresh water until the smell dissipates.
Freshen with Lemon Juice
For a citrus-fresh scent, you can wash your Hydro Flask with lemon juice. The acidity helps destroy microbes.
Combine equal parts lemon juice and water. Wash and scrub the inside of the bottle with this solution.
Rinse thoroughly afterward. The lingering lemon fragrance leaves your bottle smelling clean.
Dry Upside Down
After using any of these odor-busting cleaning methods, it’s important to dry the Hydro Flask fully upside down.
This ensures no moisture gets trapped inside, allowing smells and mold to return. Let air dry completely before next use.
How to Clean the Outside of a Hydro Flask
While the interior needs more intensive scrubbing, you can easily clean the exterior of a Hydro Flask using mild dish soap, water, and a soft sponge or cloth. Here’s how to clean the outside properly:
- Rinse the outside of the bottle under warm running water. This washes away any loose dirt or grime.
- Apply a small amount of dish soap to a soft sponge, cloth, or paper towel. Avoid abrasive scrubbers.
- Wipe down all exterior surfaces of the bottle with the soapy sponge/cloth. Apply light pressure.
- Rinse away all the soap with clean water. Wipe the outside dry with a microfiber cloth or paper towel.
- For stubborn spots, use a soft bristle toothbrush and a little baking soda to gently scrub the area, then rinse.
- Dry any wet spots to avoid waterspots. Polish with a microfiber cloth once fully dry.
- Wash the lid, straw lid, carry loop, or handle using the same method. Avoid immersing leather sleeves.
Proper drying is key to prevent mineral deposits on your Hydro Flask’s exterior. Always use soft, non-abrasive cleaners to avoid scratching the powder coat.
With regular gentle cleaning, you can keep the outside of your Hydro Flask looking like new.
Hydro Flask Cleaning Tips and Tricks
Follow these additional tips to keep your water bottle fresh and prevent damage:
- Wash your Hydro Flask after each use for best results, or at a minimum, every other day.
- Only use bottle brushes specifically designed for stainless steel – not wire scrubbies that can scratch.
- Replace your brush when the bristles appear frayed or worn.
- Always disassemble the lid and clean each piece separately.
- Use a straw brush or pipe cleaner to clean the reusable straw on straw lids.
- Avoid putting Hydro Flask in the dishwasher, as high heat can degrade the powder coat.
- For major grime, let the bottle soak in hot, soapy water to loosen residue before scrubbing.
- If smells persist after cleaning, try a thorough baking soda or vinegar soak.
- Allow to fully air dry after every wash, upside down on a dish rack.
- Give some extra attention to the rim threads and carry spots which attract grime.
- Never use bleach or harsh chemicals – mild dish soap and water is best.
How Often Should You Clean Your Hydro Flask?
We recommend cleaning your Hydro Flask water bottle after each use for maximum freshness. If you refill your bottle multiple times a day, give it a quick rinse and wash thoroughly at the end of the day.
For light use, clean your bottle every 2-3 days. Letting residue sit longer breeds bacteria.
At the absolute minimum, wash your Hydro Flask once a week with soap and water. But don’t let it go any longer than that between cleanings.
Remember to fully disassemble the lid and clean all parts during your wash sessions. Following a regular schedule prevents buildup inside your bottle.
Can You Use a Hydro Flask Straw Lid Without the Straw?
Yes, you can use a Hydro Flask straw lid without inserting the reusable straw. The lid can function as a spout for drinking from the bottle.
However, you’ll want to disassemble and properly clean the straw lid first. Food particles, oils, and bacteria can get trapped in the straw housing.
Remove any gaskets, valves, etc. and wash each piece with soap and water. Rinse and dry thoroughly.
Once squeaky clean, you can snap the lid onto your Hydro Flask and drink straight from the opening. Be sure to wash the lid fully after each use.
Leaving the reusable plastic straw inside provides an extra level of insulation for hot drinks. But it’s not required for the lid to work properly. Enjoy your Hydro Flask with or without the straw!
Does Freezing a Hydro Flask Remove Odors?
Freezing a smelly Hydro Flask overnight can help eliminate some odors, but it doesn’t fully sanitize the bottle. Freezing causes smells to becomes less volatile.
To freeze your Hydro Flask for odor removal:
- Wash the bottle first with soap and warm water.
- Fill halfway with fresh water. This gives the freezing expansion room.
- Put the lid on loosely, without tightening.
- Place in your freezer overnight. The water will fully freeze.
- In the morning it should pop right out. If not, hold under warm running water.
- Wash again with soap before first use to disinfect.
Freezing can freshen up your bottle, but be sure to fully clean it with soap and water first and afterward. Don’t rely on this method alone to sanitize your Hydro Flask.
How to Remove Stuck-On Gunk and Dried Residue
Here are some tips for removing stubborn gunk inside your Hydro Flask:
- Try soaking in warm, soapy water for 30 minutes to loosen stuck-on debris and stains.
- Use a soft sponge or rag to gently rub affected areas while soaking.
- For really stubborn gunk, let soak for 1-2 hours, periodically scrubbing. The longer the better.
- Try a baking soda paste – mix a little water with baking soda to form a paste, apply to gunk and let sit before scrubbing.
- Soak in undiluted white vinegar overnight – the acidity will help break down residue.
- When scrubbing, use a soft bottle brush and avoid anything abrasive that could scratch.
- Avoid using sharp tools or steel wool to scrape off gunk as these can damage the powder coating.
With extended soaking and soft scrubbing, you should be able to remove even the most stubborn dried-on gunk from your trusty Hydro Flask.
How to Eliminate Bad Smells from a Hydro Flask
To eliminate foul odors from your Hydro Flask water bottle, follow these tips:
- Wash with baking soda – add 1-2 tbsp baking soda and a little water, scrub interior walls.
- Soak in vinegar – fill with undiluted white vinegar and soak overnight, then rinse thoroughly.
- Scrub with lemon juice – the acidity kills bacteria that causes odors.
- Freezing can help eliminate smells – wash bottle, freeze overnight, wash again before use.
- Always dry fully upside down after washing to prevent mold and mildew buildup.
- Deep clean valves, gaskets, straws, etc. where odors can hide.
- Replace straws, lids, gaskets if smells persist after thorough cleaning.
- Never use bleach or harsh cleaners.
- Wash after each use to prevent smells from building up over time.
Be diligent about drying and regularly cleaning your Hydro Flask. Odors happen when residue sits for too long. Proper cleaning prevents stinky bottles!
How to Clean a Hydro Flask Without a Brush
If you don’t have a bottle brush, you can still clean the inside of your Hydro Flask using common household items:
- Uncooked rice – Add 1/4 cup of rice with warm, soapy water. Shake vigorously for 2-3 minutes to scrub interior. Rinse thoroughly after. The rice acts as an abrasive scrubber.
- Crumpled aluminum foil – Place a sheet of foil loosely wadded up into your bottle. Add soap and water. Shake forcefully for 1-2 minutes so the foil scours the surface. Remove foil before rinsing clean.
- Clean gravel – Use a handful of aquarium gravel or stones from outside. Add soap and water and shake forcefully for several minutes. The gravel will dislodge gunk. Rinse thoroughly.
- Salt – Coarse salt works similar to rice as an abrasive scrubber. Add 1-2 tbsp salt with soapy water and shake for 2 minutes before rinsing out.
While bottle brushes are ideal, one of these handy substitutions can get the job done in a pinch. Just be sure to rinse very thoroughly after cleaning.
How to Clean a Hydro Flask Cap
Follow these steps to clean your Hydro Flask cap properly:
- Disassemble – Remove any gaskets, valves, straws and take the cap apart into individual pieces (twist off discs, etc).
- Wash – Use warm, soapy water and a soft brush or cloth to scrub each cap component individually. Get into crevices.
- Rinse – Rinse all the cap parts thoroughly with clean water to remove residue.
- Dry – Allow to air dry fully. For straws, insert a pipe cleaner and let dry before reinserting into the lid to avoid mold.
- Reassemble – Once fully dry, put the cap back together by reattaching any gaskets, reinserting straws, twisting pieces closed, etc.
Be sure to clean your cap after each use. Pay special attention to small spaces that can trap dirty water and germs. Let all parts dry completely before snapping onto your water bottle.
Does a Hydro Flask Need to Be Washed Before First Use?
It’s recommended to wash your new Hydro Flask water bottle before using it for the first time. Here’s why:
- Removes manufacturing residues – Oils, metal shavings, dust, and other debris can be left behind during production.
- Eliminates smells – You may notice an odor from packaging materials or the manufacturing process. Washing removes any funky smells.
- Sanitizes the bottle – A thorough wash removes any germs or bacteria that may have entered from handling during transit and stocking store shelves.
- Improves bottle performance – Washing helps activate the TempShield insulation by allowing interior condensation to adhere properly.
To clean before first use, wash your Hydro Flask with warm soapy water. Scrub the inside with a bottle brush. Rinse very thoroughly with clean water and allow to fully air dry.
Starting with a freshly cleaned bottle allows you to enjoy the purest tasting water from your new Hydro Flask!
How Does Changing Elevation Affect a Hydro Flask?
Drastic elevation changes can impact the performance of a Hydro Flask’s TempShield insulation. Here’s what happens:
- At higher elevations, the boiling point of water decreases due to lower air pressure. This makes it harder for the Hydro Flask to retain heat.
- The vacuum insulation relies on differences between external and internal air pressure. When these pressures change at high elevations, insulation is less effective.
- During airplane travel, the pressurized cabin minimizes these effects. But ascending to mountain towns reduces performance somewhat.
- The insulation still works at high elevations, just not quite as well as at sea level. You may notice hot drinks cooling faster.
- The opposite is true for keeping cold drinks chilled, since lower air pressure causes contents to stay cooler longer when ascending.
While changes in elevation impacts heat retention slightly, the Hydro Flask still performs far better than a regular bottle. Consider starting with hotter water if you’ll be at high altitudes. For cold drinks, elevation changes have little noticeable effect.
Troubleshooting Leaks in a Hydro Flask
If you notice your Hydro Flask leaking, try these troubleshooting tips:
- Tighten the lid – Often loose lids are the culprit. Make sure the lid is rotated on tightly. Hand tighten only.
- Clean the gaskets – Dirty or worn gaskets can cause leaks. Remove and clean gaskets thoroughly. Replace if damaged.
- Check for cracks – Carefully inspect bottle and lid for any cracks. Even small cracks can cause leaks and need replacement.
- Ensure straws are sealed – Push straws fully into grommets in lid and confirm they are engaged