Why Does My Kitchen Sink Smell Like Rotten Eggs or Sulfur?

Sometimes when you walk into the kitchen, you are met with an almost invisible force of unimaginable magnitude right smack dab in the middle of your nose of all places.

What was that, you wonder? Well, there are several different reasons there could be a funky smell coming out of your drain in the kitchen sink. Most of the time, you will immediately identify the smell as coming from either rotten eggs or something else rather sulfurous.

These smells are not uncommon but need to be dealt with to make your kitchen usable again. At least to make your kitchen usable without needing to wear a clothespin over your nose.

Source Of The Sulfurous Smell

kitchen sink drain

There are several different sources that the smell could be coming from underneath your kitchen sink.

Each source may smell slightly differently, but they share similar overall sensory profiles between all of the different sources. Identifying the exact origin of the smell is the first step to correct the issue.

Gas From The Sewer

Your kitchen sinks plumbing lines are connected to the sewer. Typically, there is a particular structure within the kitchen sink’s pipes called a drain trap that prevents the gases from the wastewater wafting up the pipes and into your kitchen.

If you installed your kitchen sink or an inexperienced installer did the work, then it’s possible this portion of the kitchen sink’s piping was not done correctly. An improper fit lets the gas from the sewer into your home unimpeded.

Lack of Water In The Drain Trap

sink drain trap

The drain trap is the U-shaped section of the pipe underneath the sink. Usually, in this part of the pipe, water will pool together and sit there idly.

This prevents gas from flowing up the pipe into the kitchen, stopping smells from entering your home.

Sinks that have not been used for extended periods may have all of the water in this section of the pipe evaporate. If there is no water, there is no longer a barrier preventing smells from entering the house, and it needs to be replaced in the drain trap.

Decomposing Lipids Stuck Within The Drain

Fats that are leftover from cooking and poured down the sink are referred to as lipids and can become stuck even if you run water down the drain because they are hydrophobic.

This fat will collect together and form a thick substance along the sides of the pipe. Since this is an organic material, it will be decomposed by microorganisms that live in your kitchen sink.

The decomposition process releases sulfur compounds that smell horrendous to people. Do not pour grease down your sink if you want to avoid this.

Your Plumbing Vent Is Backed Up

The vent to your plumbing can get clogged by many different things. If something does end up clogging the vent that to your plumbing, the sewer can have its smell leak right into your home.

Ensure the vent to your plumbing is unblocked if you notice any strange smells coming from the kitchen sink, but are unable to identify the source otherwise.

The Garbage Disposal Has Not Been Emptied

garbage disposal full

Finally, perhaps the most common reason that kitchen sinks end up smelling like decomposing food is that there is decomposing food in the garbage disposal from the last time it was used.

Garbage disposals do not instantaneously vaporize food, and they need time to break it down. People will often turn them off before getting rid of the food, leaving bits stuck to the disposal unit itself.

Every so often, you can try to throw a couple of citrus fruits into the garbage disposal cut into small bits and letting it run for a wild along with some warm water. The combination of the fruit peel and the acid of its juice will help to clean the blades of the garbage disposal and leave a nice tropical smell instead of the smell of rotten eggs.

What To Do About The Smell Coming From Your Kitchen Sink

So you have gotten your hands dirty and found out what’s causing the smell emanating from your kitchen sink that is so vile. What are you supposed to do now?

The answer to that question will depend on the smell’s source, but overall the process will look pretty similar no matter what the source of the smell is.

Repair Any Damages To The Plumbing Vent Or The Drain Trap

First, things are first if you detect any damage to the plumbing vents or the drain trap; these need to be addressed immediately.

Even if it was another problem that caused the initial smell, if these are left unattended to another scent will eventually develop guaranteed.

Use An Enzymatic Drain Cleaner

Since many of the smells result from the decomposition of leftover food bits stuck within the kitchen sink pipes, it is possible to use particular cleaning agents to break the remaining bits down and get rid of the items causing the smell. We recommend this drain cleaner available at amazon.

Organic molecules can be broken down by compounds called enzymes that occur naturally within our bodies and the environment. You should be able to find something called an enzymatic drain cleaner at your local hardware store.

These are designed to break down the remaining food bits that get stuck within the kitchen sinks by breaking them down chemically. They do take a little while for them to work, but they usually are very effective.

Request Professional Help To Sanitize Your Kitchen Sink

Of course, you can always rely on a high quality professional to come out and the service your kitchen sink if you feel incapable of doing so yourself.

Often, this is the best option because you can avoid getting face to face with the smell, especially if you find it to be overpowering. Please make sure any companies you work with are well-reviewed and have excellent reputations before you make any commitments; otherwise, this is probably the way to go.