The best way to clean a garbage disposal is pretty straight forward. In theory, garbage disposers are self-cleaning, but it doesn’t always work that way. This article will walk you through the steps for garbage disposal cleaning and keeping the rotting food smell from coming back.
First, a little background on how garbage disposers work and why they sometimes smell like something died down there will be helpful. Wisconsin architect John Hammes came up with the idea in 1927 when he saw the mess involved in disposing of food waste after of meal.
Beyond the mess, food wastes posed a health risk by attracting insects and rodents while providing a breeding ground for bacteria. Hammes’ invention went to market a few years later, making homes healthier and dramatically reducing the methane gasses emitted by landfills.
How a Garbage Disposal Works
A common misconception is that a garbage disposer works like a blender, with sharp blades that chop and cut food waste to reduce it to a liquid state. Wrong.
Instead, garbage disposers grind food to a gooey slurry that runs directly to sewer systems. As you push food waste into the disposer it falls on a turntable spinning at 1,400 – 1,800 RPM that throws it against a grind ring that has holes with sharp edges.
The turntable has two impellers that swivel rapidly, hammering the food waste against the sharp edges. This brief video by Insinkerator (the company John Hammes founded) illustrates how a garbage disposal works.
Why Does My Garbage Disposal Smell Bad?
Garbage disposals sometimes smell bad because food is rotting in the disposer or the plumbing beneath it. Why food collects there instead of being completely ground up and carried to the sewer is the question to ask yourself.
Garbage disposal is too small – Some food waste disposers work better than others. Size maters. A 1/3 horsepower disposer will cost less up front but will be prone to jamming, and it will not grind as well.
A 1/2 horsepower unit should be the minimum for most homes, and you may the difference between that and a 3/4 horsepower garbage disposer is worth the price difference. Bigger units are quieter, grind finer and work faster. This article by Consumer Reports discusses the pros and cons of different sizes and types of garbage disposals.
Disposal needs to be “sharpened” – Over time, a steady diet of soft foods will reduce the effectiveness of the grind ring’s cutting edges. The hard steel edges don’t get dull so much as they become coated with a combination of food particles, grease, oils, fat and starches.
Fibrous food waste, such as banana peels, onion skins, celery or asparagus, are even worse for your disposer. They require more time to process and often cannot be completely ground up, leaving more residual waste sticking to your disposal, making it dull.
Most larger home garbage disposers can grind potato peels fine. The problem is the gooey mess they create in drain lines, which acts as the glue to hold food waste particles together to form a clog. This article discusses things that should never go down your drain or through your garbage disposal.
The bottom line is that instead of sharpening your garbage disposer you really need to clean it. We’ll get into the details below.
Improper installation – it is rare, but sometimes we find a garbage disposal that has not been properly installed, especially when done by do-it-yourself homeowners who did the job almost right.
Before You Start – Safety First
Disconnect power – Before you peek down the top, unplug it. There should be an electrical outlet beneath the sink that supplies the power. In case there is none, shut off the power at the circuit breaker. After you’ve done that switch the disposal on to be sure it has no power.
Keep fingers out – Do not reach into the disposal grind chamber. Garbage disposers don’t have sharp blades, but the cutting edges of the grind ring are sharp and easily can cut you. If the chamber is coated with sludge you can get a bacterial infection.
Another reason not to reach into the chamber is that you may get a nasty surprise, such as broken glass or dinnerware, a bottle cap, or a pull tab from a soda can. Try to remove any objects with tongs or long-handled pliers. If you cannot remove it, get a plumber.
If the unit is stuck and won’t turn, remove the splash guard and shine a flashlight into the chamber to visually inspect it. NOTE: not all splash guards can be taken out this way; some require removing the entire garbage disposer from its mounting to get access to it. (That is when most people hire a plumber.) If the splash guard is in good shape, use a flat stick to hold it out of the way.
How to Clean a Garbage Disposal in 5 Steps
Now, with fingers intact and any foreign objects removed, it’s time to take care of the rotting food smell that caused you to wrinkle up your nose in the first place.
You may have seen commercial products to clean a garbage disposal in hardware or big box stores. Don’t waste your money. Most of them only tackle part of the problem. Follow these steps to get great results.
1. Clean the Rubber Splash Guard
The top side of the rubber splash guard may look clean, but the bottom side is likely to coat coated with slime. Clean it while you have the power turned off.
Make a paste of baking soda and vinegar (be prepared for the initial fizzy reaction) and apply it with an old toothbrush to scrub the top and underside of the splash guard and along the neck of the opening.
If your splash guard isn’t the kind you can remove from the top, pull up the splash guard a section at a time so you can get to the underside.
Now it’s time to turn the power back on.
2. Wash Disposer with Hot, Soapy Water
Place the stopper in the top of the garbage disposal and fill the sink most of the way with hot water with a few drops of dishwashing detergent in it.
Normally, we don’t recommend putting hot water in a food disposer, but to clean a garbage disposal, it’s a good idea. Remove the stopper and turn on the disposer. Leave it on until all the hot water has gone down the drain.
3. Grind Ice Cubes and Rock Salt
A bigger source of garbage disposal odor comes from the built-up yuck that coats the grind ring and turntable. The hot water wash cycle should have loosed that up somewhat, so not for some serious abrasive action.
Drop about a dozen ice cubes into the garbage disposer and add a half-cup of rock salt. The bigger size of the rock salt helps prolong the rubbing action.
Turn on the hot water and the garbage disposal. Let it run for a minute or so to rinse the grinding chamber. Then disconnect the power again. Look down the drain again to see that the grind ring, turntable and impellers are clean. If so, reconnect the power.
4. Scour with Vinegar and Baking Soda
Now for the effervescent treatment. Pour a cup of white vinegar and a half-cup of baking soda down the drain and into your disposer. Let it sit and fizz for 15 minutes to kill bacteria, including salmonella and E-coli), as your thoughts drift back to your school science class volcano.
It’s important not to use any toxic chemicals during this step. We do not recommend ever using them for cleaning drain lines or loosening clogs. They are caustic and can damage your home’s plumbing system, and they can contaminate rivers and lakes.
Disconnect the power and inspect again. If still not clean, repeat the wash cycle (Step 2).
5. Freshen with Lemon Power
The finishing touch when you clean a garbage disposal is giving it a fresh, pleasant smell. Turn on the disposer and feed some small pieces of citrus peels through it after it’s running. You can use a lemon or lime or even an orange or grapefruit.
You also can use three or four thin slices (about 1/8-inch) of citrus fruit with rind attached. Large pieces can cause be too much to grind and can cause food waste to start sticking to the grind ring again – not what you want.
Still Need More Cleaning?
If for some reason these five easy steps to clean a garbage disposal don’t get you the result you wanted, you may want to try these additional steps.
It’s OK to also rinse a little bleach down your kitchen drain. Bleach is very effective at killing germs, removing bacteria and freshening up your drain. Don’t use too much because it can harden any grease that may be down there.
Dilute one tablespoon of liquid chlorine bleach in a gallon of water. With the switch off, slowly pour it into the garbage disposer. After it sits for a few minutes, flush it with some hot water for several minutes to make sure you wash away the bleach.
Also, Borax can be used as a natural cleaning product to help clean a garbage disposal. You can also use four tablespoons of Borax in the garbage disposer and allow it to sit for about an hour. And, again, use hot water to flush it away.
Consider these extra steps only if absolutely necessary.
The key takeaways for how to garbage disposal cleaning are:
Safety first – disconnect the power supply, keep fingers out of the disposer.
5 Steps for Garbage Disposal Cleaning:
- Clean the Rubber Splash Guard – don’t overlook the obvious. The top may look clean, but slime lies beneath
- Washing with hot, soapy water – soften up built-up sludge first
- Get abrasive with ice cubes and rock salt – knock off the loosened crud
- Scouring and disinfecting with vinegar and baking soda – kills harmful bacteria, including E-coli and salmonella
- Freshen up with lemon – add a fresh, clean smell by grinding small pieces of lemon peel
Now that you have a clean garbage disposal that is odor free, try to keep it that way with regular cleaning. Prevention is always better than repair or replacement.
Got some tips we haven’t thought of for garbage disposal cleaning? Please contact us to pass them along and we will share them.