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Blender Smells Bad? Why Rubber Gaskets Hold Odor and How to Reset

The rubber gasket and blade base trap milk and food, then go sour. Take it apart, soak it and dry it fully, then brush the spots a sponge never reaches.

By Jamilur Rahman Updated November 5, 2026 · 6 min read

Time
30 min
Cost
Under $20
Difficulty
Easy
A blender pitcher upside down on a counter with its blade assembly removed and a dark rubber gasket beside it
In this guide
  1. Quick answer
  2. Free vs. permanent fix
  3. What you'll need
  4. Why it happens
  5. Try this first (free)
  6. When free fixes aren't enough
  7. Buy the fix
  8. Why does my blender smell? Check these four spots
  9. What to skip
  10. FAQ
  11. Related problems

Quick answer

Why does my blender smell bad? Usually it is the rubber gasket and the base under the blade, where milk, fruit and protein powder hide and go sour. If your manual allows it, take the blade assembly apart, soak the parts in warm water with vinegar, scrub with a brush and let everything dry before you store it. A bottle brush keeps the hidden spots clean after that.

Free fix vs. permanent fix

Free fix · 30 minutes, mostly soaking

Take it apart, soak it, dry it fully

  • Unplug it and separate the pitcher, ring and gasket
  • Soak the parts in warm water with a splash of white vinegar
  • Scrub the gasket groove and the base under the blade
  • Dry everything and store the pitcher with the lid off

How long it lasts: Weeks, if you rinse right after use and let the parts dry. The smell returns when wet parts stay closed up.

Most readers choose Permanent fix
Bottle brush set for blender pitchers (illustration)
Illustration

A bottle brush set made for blender pitchers

The smell comes from small amounts of residue in spots a sponge cannot reach: under the blade, in the gasket groove and in the narrow base of the pitcher. A thin brush gets in there at every wash, so nothing sits long enough to turn.

What to get: Bottle brush set for blender pitchers

How long it lasts: Years. Use it each wash and residue never gets time to sour.

Check price on Amazon

As an Amazon Associate I earn from qualifying purchases.

What you'll need

  • Dish soap

    Hot water and a few drops are enough

    You have it

  • White vinegar

    Mix about 1 part with 3 parts warm water for the soak

    You have it

  • Baking soda

    For a paste on stubborn spots and a final rinse

    You have it
  • Our pick
    Bottle brush set for blender pitchers (illustration)
    Illustration

    Bottle brush set for blender pitchers

    A long brush for the pitcher and a small one for the base

    Check price
  • Replacement blender gasket (illustration)
    Illustration

    Replacement blender gasket

    Only if the old one is stained, sticky or cracked. Match it to your model

    Check price

Why it happens

1

Residue under the blade

Milk, yogurt, banana and protein powder get pushed into the base and the thread under the blade. A quick rinse never reaches them, and they turn sour in a day or two.

2

A gasket that absorbs odor

Soft rubber takes up fats and oils from what you blend. It can hold a sour smell even when it looks clean, so washing the pitcher alone does not help.

3

Parts stored wet and closed

A pitcher put away with the lid on, or a gasket left inside a damp base, stays moist. That is what lets sour smells and mildew build.

4

Plastic that holds strong flavors

Garlic, onion, coffee and spices leave oils that soak into plastic pitchers. Those smells fade slowly, even after a thorough wash.

Try this first (free)

Do these in order, starting with the simplest.

  1. Unplug it and take it apart

    Lift the pitcher off the base. If your manual says the blade assembly comes off, unscrew it with care, since the blades are sharp, and pop out the gasket. Never put the motor base in water.

  2. Soak the gasket, ring and lid

    Tool used: White vinegar

    Drop them in a bowl of warm water with about a quarter cup of white vinegar per cup of water. Leave for 15 to 30 minutes, then rinse well.

  3. Scrub the hidden spots

    Tool used: Bottle brush set for blender pitchers

    Use a bottle brush and dish soap on the gasket groove, the underside of the blade assembly and the narrow base of the pitcher. Rinse under hot water until nothing feels slimy.

    Bottle brush set for blender pitchers (illustration)
    Illustration

    Tool for this step

    Bottle brush set for blender pitchers · A long brush for the pitcher and a small one for the base

    Check price on Amazon

  4. Do a baking soda rinse

    Tool used: Baking soda

    Put the parts back together, add a tablespoon of baking soda and two cups of warm water, and blend for 30 seconds. Let it sit for 10 minutes, then rinse.

  5. Dry it and store it open

    Stand the parts on a rack until fully dry. Store the pitcher with the lid off or ajar, and keep the gasket out of a closed base while it is damp.

When free fixes aren't enough

If the gasket still smells after a vinegar soak and a scrub, or if it looks stained, sticky or cracked, replace it. Soft rubber cannot always be cleaned after it absorbs oils, and a worn gasket also leaks. If you see dark mold spots in the base that do not scrub off, replace the part. A burning smell from the motor base while you blend is a different problem: stop, unplug it and contact the maker.

Buy the fix

Still stuck after the free fixes? These are the products we would look at.

Our picks compared
PickProductFixesWho it's forBuy
Best pick
Bottle brush set for blender pitchers (illustration)
Illustration
Bottle brush set for blender pitchers
hidden residue that turns sour Anyone who blends milk, yogurt or protein shakes often, and cannot reach the base with a sponge. Check price
Upgrade pick
Replacement blender gasket (illustration)
Illustration
Replacement blender gasket
a gasket that holds odor or leaks after a deep clean Anyone whose gasket still smells after a soak, or looks stained, flat or cracked. Check price
Best pick
Bottle brush set for blender pitchers (illustration)
Illustration

Bottle brush set for blender pitchers

Fixes: hidden residue that turns sour

Look for: A long brush that reaches the bottom of a tall pitcher; A small detail brush for the gasket groove and blade base; Soft bristles that will not scratch plastic or glass.

Who it's for
Anyone who blends milk, yogurt or protein shakes often, and cannot reach the base with a sponge.
Honest downside
You only blend water-based smoothies and already scrub the base. Your own brush may be enough.
Check price on Amazon
Upgrade pick
Replacement blender gasket (illustration)
Illustration

Replacement blender gasket

Fixes: a gasket that holds odor or leaks after a deep clean

Look for: A part that is listed for your exact blender brand and model; Soft, flexible rubber with no cracks; A ring or washer shape that matches the original.

Who it's for
Anyone whose gasket still smells after a soak, or looks stained, flat or cracked.
Honest downside
You do not know your model number. Find it on the base before you buy.
Check price on Amazon

As an Amazon Associate I earn from qualifying purchases. We don't show prices because they change, so use the button to see today's price.

How we picked: How we picked: this page is based on blender owner manuals and cleaning guides, how appliance makers describe gasket care, and the problems and fixes people report in owner reviews. We do not test products by hand.

Why does my blender smell? Check these four spots

  • The gasket: sniff it out of the pitcher. If it smells sour on its own, it is the source.
  • The blade base: residue builds in the thread and under the blade.
  • The lid and ring: milk sits in the groove around the lid seal.
  • The pitcher itself: plastic can hold strong odors after garlic, onion or coffee.

What to skip

Scented sprays and perfumed soaps

Masking the smell does not remove the residue under it, and the scent can end up in your smoothie. Take the parts apart and clean them instead.

Frequently asked questions

Blender smells sour. Is it safe to use?
A sour smell usually means old milk, fruit or protein residue is sitting in the base. Clean the parts as above and use it once they smell clean. If you see mold or the smell stays after a deep clean, replace the gasket.
Blender smells like rotten milk. How do I get it out?
Milk fat clings to the gasket and the base. Soak the gasket in warm water with vinegar, scrub the base with a bottle brush and dish soap, rinse well and dry completely.
How to stop blender from smelling?
Rinse right after you use it, blend warm water with a drop of dish soap for 30 seconds, rinse again and let the parts dry before closing the lid. A weekly teardown of the gasket keeps the smell from returning.
Why does my blender cup smell bad even after washing?
The smell may be coming from the gasket or the base under the blade, not from the cup. Take them off, soak and scrub them. Strong foods such as garlic or coffee can also stay in plastic, so a baking soda soak helps.

As an Amazon Associate I earn from qualifying purchases. Affiliate disclosure

Bottle brush set for blender pitchers (illustration)
Illustration

Our pick: Bottle brush set for blender pitchers

Check price