Having a garbage disposal in your kitchen can come in handy when preparing and cleaning up after Thanksgiving dinner. However, garbage disposals are also major contributors to clogs and plumbing problems simply because many people don’t use them correctly and treat them like trash cans. Having your sink suddenly clog up when you’re halfway through doing the dishes can be a nightmare, so you must use your garbage disposal properly and know what types of food can go down a disposal and what should always go in the trash.

Fat, Oil and Grease

Even with a garbage disposal, you should never pour any fat, oil, or grease down the drain. Fats, oils, and greases are some of the biggest sources of major plumbing problems, as they tend to slowly collect inside of pipes and eventually cause what plumbers call a FOG (fat, oil, and grease) clog.

Fat, oil, and grease aren’t water soluble so they tend to cling to the inside of pipes instead of being washed out into the sewer system. Think about how oil clings to a measuring cup or how leftover grease sticks to a plate. Just as oil and grease can cling to dishes and be tough to wash away, they’ll also cling to your pipes and never get fully washed out into the sewer system. The more oil and grease you put down the drain, the thicker the greasy coating inside of the pipes will get. Liquid fat and grease will also solidify and set up into a thick blob as they travel through your pipes.

Any fat, oil, and grease that sits inside pipes can easily trap food scraps, toilet paper, and any other solids that go down the drain. This can eventually result in a clog forming that prevents the water and waste from draining and leads to it backing up and possibly overflowing out of your showers and floor drains.

Potatoes and Other Starches

Any starchy foods like potato peels, potatoes, yams, bread or stuffing, beans, rice, and other grains should also always go in the trash. A garbage disposal can easily pulverize starchy foods, but all that happens is that they turn into a gluey mass that can be almost impossible to flush down the drain. If you put potato peels or pieces of potato in a garbage disposal, it will make extremely thick, sticky mashed potatoes. Some of the starchy mass will stick to the insides of the garbage disposal, but most of it will often get stuck in the bend in the P-trap underneath the sink. Any other food that goes down the drain can then also get stuck and quickly lead to the drain pipe clogging.

Turkey Bones

Contrary to popular belief, garbage disposals don’t have blades that chop food up. Instead, they work by grinding up or pulverizing the food. Inside the disposal are two impellers that are mounted onto a plate. When you turn the disposal on, the plate spins and the impellers produce centrifugal force that sends the food scraps flying into a stationary grinding ring that surrounds the plate.

Garbage disposals can’t handle hard items like turkey bones, fruit pits, shells, etc. Bones and other hard items typically won’t get fully pulverized and could easily get lodged inside the drain pipe, leading to a clog. They can also easily bind up or jam the impellers so the plate won’t spin and the disposal stops working. This can be a serious problem, as the motor can quickly overheat and burn out if you try to continue running the disposal when it’s jammed. Hard items will also dull the fins on the grinding ring, leading to the disposal not working as well and shortening its lifespan.

If your disposal does get jammed, shut it off immediately. Then you can unplug it and see if you can clear the jam. This is done by inserting an Allen wrench or hex key into the slot on the bottom of the disposal. Move the wrench back and forth until you can get it to turn one full revolution. This will usually loosen and free up whatever hard item was stuck and jamming the plate. Once the plate is free, use a flashlight and look inside the disposal to see if you can find what was jamming it up. If you can see the item, you’ll usually be able to pull it out with a wooden spoon or tongs. If you can’t see anything, you can try to turn the disposal back on to see if it now spins properly.

Eggshells and Onion Skins

Eggshells are brittle enough that a garbage disposal can easily break them up. The problem isn’t the shells themselves, but the slimy membrane inside of them. When you run eggshells through a garbage disposal, the membrane will often stick inside the drain so that it drains more slowly or doesn’t drain at all. This same issue is why onion skins also shouldn’t go in a garbage disposal since the membrane inside the skin can also get stuck in the drain.

Pumpkin and Fibrous Vegetables

When cleaning a pumpkin or any type of squash, you’ll want to scrape the seeds and slimy insides in the trash and also toss the rind in the trash. Any other fibrous vegetables like celery and green beans should also never go in a garbage disposal. The issue here is that the long, stringy fibers can easily get wrapped around the impellers and jam up the disposal. If this happens, you’ll again have to use the wrench to unjam the disposal so that the impellers again spin freely.

Seeds and Nuts

Nuts and seeds are soft enough that the garbage disposal will easily grind them up into a thick sticky paste. When you put any type of nut or seed in your garbage disposal, it’s no different than using a food processor to make peanut butter. The paste that forms will stick inside the disposal and clog up the drain holes or get stuck inside the drain pipe and increase the chances of it clogging.

Coffee Grounds

If you’re making coffee to have with your dessert, you also want to make sure to dump all of the wet coffee grounds in the trash. Water will easily flush coffee grounds through the disposal. The problem is that wet coffee grounds are extremely dense and will often get stuck inside the P-trap or further down in the drain pipe.

Having your plumbing system inspected and your drains cleaned before the holidays is an easy way to prevent clogs and other plumbing problems. At Plumbtree Plumbing & Rooter, we specialize in drain cleaning and all plumbing, drain, and sewer repairs, and our team can take care of any problems you have to help avoid major issues arising. We’re available 24/7 so you can also count on us should your sink clog up during Thanksgiving or if you have any plumbing or sewer problems at any time of the year, day or night. For more information on what makes us the top-rated plumbing and sewer service in the Sacramento area, contact Plumbtree Plumbing & Rooter today.

Josh Gibson

Hi, I’m Josh. I’ve been around plumbing my whole life. When I was 5-6 years old my family built a home where I did a lot of the sanding of copper pipe and definitely some playing in the mud. Plumbing is a major part of my family as I am a fourth-generation plumber. The skills I bring to the job are a good technical knowledge of plumbing and code requirements. I am often complimented on my hands-on problem-solving skills.
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