Why Does It Stink Under My Kitchen Sink?

Perhaps you’ve noticed an unpleasant odor in your kitchen for the past few days but have been unable to pinpoint its origin. However, once you opened the cabinet door beneath your kitchen sink to grab dish soap, you found the source of the pungent smell. So, what’s causing the smell?

Finding its origin was the first step, but how do you fix it? We’re here to help – in this article, we discuss common causes of smelly sink cabinets and how to correct the issue, so continue reading to learn more!

What Causes The Cabinet Underneath My Sink To Smell?

A few potential culprits can cause the space underneath your sink to smell, although a few are more common than others. Here are a few of the most common causes of a stinky odor beneath your sink:

Rotting Food

Sometimes, the smell might be emanating from your garbage disposal. In most cases, you’ll notice strong odors above the sink, near the drain, but they might seem to fill the cabinet beneath your sink. 

When the garbage disposal is the problem, there’s likely food buildup in the canister or drainpipes. As the food particles begin to rot, it creates a strong, unpleasant odor that overtakes the area. Although garbage disposals are effective for clearing most food scraps, there are some scraps it can’t handle (oil, grease, fats, potato peels, fibrous fruits and veggies, etc.). 

Mold And Mildew

Musty smells beneath your kitchen sink are usually the result of mold and mildew colonies. Mold and mildew will take hold when the drain or plumbing beneath your kitchen sink springs a leak. In severe scenarios, the water leak can be large enough or go on for long enough, creating significant water damage in the cabinet below. 

That said, even a tiny leak in the plumbing can create the perfect environment for mold and mildew. The moisture in the cabinet is ideal for mold, and once these colonies develop, they create a musty smell. 

P-Trap Issues

If the smell coming from the cabinet smells like sewage or sewer water, it’s likely an issue with the P-trap. The P-trap is the U-shaped piece in the plumbing assembly beneath your sink. The bottom of the “U” holds water, which prevents sewer gases from entering your home via the plumbing. 

However, when this trap malfunctions or doesn’t contain water, sewer gases can seep into your home, including the space beneath your sink. 

How Do I Get Rid Of The Smell Under My Kitchen Sink?

The unpleasant odor beneath your sink is likely an unwelcome guest in your kitchen, so once you find the source of the problem, it’s time to get rid of the smell. Here’s how to remedy the most common culprits of smelly kitchen sink cabinets:

Clean The Garbage Disposal

If the garbage disposal is the origin of the smell, you’ll need to clean the rotting food from the disposal. You can use a few methods to tackle the odor, including citrus rinds, baking soda and vinegar, or salt and ice. Here’s how to do each method:

Citrus Rinds

Lemons, grapefruits, oranges, and limes contain fresh-smelling oils in their rinds. So, use them to your advantage and tackle those odors from your garbage disposal. Here’s what you’ll need:

  • Lemon, grapefruit, orange, or lime
  • Cutting board and knife 

Carefully peel the rind from the fruit of your choice. Chop the rind into smaller pieces, so it doesn’t tangle around the disposal’s impellers, then toss them into the canister. You can also chop the rest of the fruit into smaller pieces and throw that in the drain, too. 

Turn on the cool water and run the garbage disposal. As the disposal crushes the rinds, they’ll release pleasant-smelling oils, which will help tackle the strong smell in the disposal. 

Baking Soda And Vinegar

These two ingredients create a powerful cleaning duo – use them to brighten laundry, clean a dirty bathroom, keep your fridge fresh, or deodorize your garbage disposal. Here’s what you need for this method:

  • Baking soda
  • Vinegar

Pour half a cup of baking soda into the disposal’s canister, then follow up with one cup of white vinegar. The combination will create a fizzy reaction in the sink drain. Allow the reaction to take place, giving it about five minutes to work. Turn on the cool water and run the disposal to flush the residue out of the canister. 

Salt And Ice

If you don’t have the above ingredients on hand, try using salt and ice. Here’s what you need for this method:

  • Salt 
  • Kosher or rock salt

Pour a large cup of ice into the canister of your garbage disposal. Add a few tablespoons of salt into the canister, then turn on the appliance. As it grinds the ice and salt, the food on the sides of the canister should begin to loosen. Once they loosen and fall from the canister, they can freely go down the drain.

Once the disposal is almost done crushing the ice, turn on the cold water and let it flush the remnants from the canister. 

Fix The Leak

You probably have a leak beneath your sink when the smell is musty instead of rotten. If you catch the issue fast enough, you might not have a large mold or mildew problem yet. However, if you do, you’ll need to clean those colonies out and dry the cabinet. Here’s what you’ll need:

  • Parts and tools to correct the leak
  • White vinegar
  • Spray bottle
  • Stiff-bristle brush
  • Rag
  • Box fan (if you have one)

First, you need to find and repair the leak. Otherwise, you’ll be back to square one within a few weeks. So, start by fixing the leak (if there are a lot of molds, remove the mold first, as it can create a hazardous working environment). 

To clean the mold, add distilled white vinegar to a spray bottle. Spray the affected areas of the cabinet with a solid coating of vinegar, then let it sit for an hour. After an hour, scrub the area with a stiff-bristled brush. Wipe away the residue with a damp rag, then dry the area with a dry cloth. 

If you have a box fan, set it up near the cabinet to dry out the area. Otherwise, leave the cabinet doors open until the space is completely dry. 

Check The P-Trap

In some cases, the odor underneath your sink might smell like sewage, which means the problem likely lies with the P-trap. Here’s what you’ll need for this project:

  • Bucket
  • Pliers or wrench
  • Long screwdriver
  • Scrubber or bottle brush
  • Dish detergent

Start by turning off the water to your kitchen sink by turning both valves clockwise. Once the water is off, place a bucket underneath the P-trap. Using pliers or a wrench, unthread the nuts holding the P-trap in place, then remove the entire U-shaped piece. Dump any water into the bucket. 

Set the P-trap aside for cleaning, then use a long screwdriver to scrape out any gunk inside the remaining pipes under your sink. Clean the P-trap with dish detergent and warm water, using a scrub pad or bottle brush to reach into the piece. Once you clean it, reattach the trap to the assembly, securing the nuts tightly in place. 

Turn the water back on and check for leaks underneath the sink. When you turn on the water, the P-trap will fill again with water, which should prevent sewer gases from coming up the drain pipes.Why Does It Stink Under My Kitchen Sink?

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