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Your garbage disposal is an incredibly important appliance that gives you a safe and sanitary way to dispose of food waste. Garbage disposals cut down on pest invasions, keep household odors to a minimum, and even help you improve your indoor air quality by reducing things like mold and mildew growth. However, they’re not impervious to issues, and they do require some care in order to use properly.

You can’t throw anything and everything down a garbage disposal. Certain types of foods can actually present some problems for either your garage disposal itself, or the plumbing lines which support it. On this blog, we’ll discuss five foods you should never throw down your garbage disposal and why not.


One of the first types of food you shouldn’t put down your drain are starchy foods, like potatoes. Starchy foods react with water and grow, swell, or become sticky. This means that they not only stick to the inside of your garbage disposal, but to the inside of your plumbing walls as well. This makes starchy foods one of the leading causes of drain clogs in plumbing lines behind garbage disposals—they’re often what first sticks to the walls of your plumbing and starts to clog your drain for good.


Asparagus is just one example of foods which are stringy, or have a fibrous texture. The reason why these are not good to put down the drain is because they can actually jam your disposal. Have you ever seen what happens when you roll a desk chair wheel over a piece of string or a thread from a carpet or piece of clothing? It seemingly gets tangled instantly. This happens even faster with your garbage disposal, which spins hundreds or even thousands of times per minute. Unjamming your disposal is possible, but an annoying and sometimes difficult plumbing procedure, and that’s assuming the jam hasn’t destroyed your garbage disposal’s motor.


Eggshells, seafood shells, or any other type of solid but inedible food is the third type of food you should never put down your drain. There’s a popular myth out there which says eggshells can help sharpen your blades in your garbage disposal, but this isn’t exactly true. In fact, they pretty much don’t do anything for your disposal, and they have been found to greatly contribute to clogs in the pipe behind your disposal. Other foods tend to stick to eggshells really well, and their jagged edges make them catch on to many different things with ease.

Coffee Grounds

Coffee grounds are another type of food that you should never put down the disposal. Coffee grounds have a similar texture and tendency to starchy foods—they can stick together when they get wet, and stuck together coffee grounds tend to accumulate quickly, rapidly forming a clog. Not to mention they can actually also become stuck in your garbage disposal itself, where they can rot and start to emit a strong odor in your kitchen. Finally, coffee actually has a fairly acidic pH level, which means that it could actually corrode the inside of your disposal.

Bacon Grease

You’ve probably been told “just pour it down the drain while running hot water when getting rid of bacon grease. Don’t do this—fat tends to solidify in plumbing lines when it makes contact with a cold, metal surface, and in many cases the water that starts out as hot when it comes out of the tap has cooled off to the point where it’s ineffective by the time it does. The fat quickly sticks to the walls of your plumbing, or other forming clogs, where it acts like glue to hold it all together, and even helps build up the clog even more. Before long, you’re dealing with an extremely difficult clog to remove. This is true for any type of fatty food, including beef, pork, and more.

If you’ve got an issue with your garbage disposal, have it fixed by the Sterling plumbing experts at Donmar Heating, Cooling & Plumbing. Call us today at (703) 457-8676 to request a service estimate.

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