Can I Put Coffee Grounds In The Sink?


It is to no surprise that you will eventually find your sink full of coffee grounds. Few grains should not be a problem, but long term accumulation of these together with other things and water may clog your drains. 

This problem is a true breeding ground to bacteria. And of all places, you would want your kitchen to be as clean as possible.

Coffee grounds down the sink

Since coffee grounds have absorptive capacity, they may trap debris, oil, and eggshells down your pipe. It wouldn’t even take decades for it to do so. Thus, coffee grounds should never end up down the sink. That’s the utter truth.

Coffee grounds end up clumping together when mixed with the water in your sink. When this continually happens, it will just be a matter of time until your drains get obstructed. The trash can is the best place for your coffee grounds to go. But, if you have a green thumb, they also work well as fertilizers! Better for your sink, better for the environment.

Things that should also end up in your trash can are:

  • Oil, grease, and fat
  • Fibrous items like eggshells, fish skins, banana peels, and celery
  • Starchy foods like rice, pasta, and potatoes
  • Anything else that isn’t edible

Basic plumbing

Usually, you can find your pipes under the kitchen sink, utility, or bathroom. These pipes are held in place by various fittings. A set of these pipes take waste water out of your home and into the septic tank. Once your pipes clog along the way, just imagine the disaster!

Solvents for coffee grounds

two clean white tea cups near metal sink 94863 1475

Although there are various cleaning agents available in the market to dissolve coffee grounds, be cautious since they typically contain harsh chemicals. An alternative is to use baking soda and vinegar. Simply pour some baking soda into the plughole followed by vinegar. It will create a foam that will help you work through your pipes. Chemistry is fun!

In a rather severe case, you might need to repeat this process a few times. If that doesn’t work, you can also consider leaving the baking soda and vinegar sitting in your pipes for an hour.

Unclogging 101

It’s easy and pretty convenient to just buy some cleaning chemicals off the shelf. However, a lot of variants contain substances that might corrode your drain line hastening wear and tear. You may want to try these methods:


Home stores have drain snakes for recent which you can use the mechanically snake the line in an attempt to unclog the pipe. It is relatively easy and simple to do but it’s of importance to do some research about the method for higher chances of success. Some of the things you should be knowledgeable about are basic plumbing and how to determine where the clot is located.


If the clog is not caused by some nasty grease accumulation, you may want to try plunging. This is possible if your sink has two sides. Simply cover the side that’s clog-free and vigorously plunge on the other clogged side. If the buildup is not as intense, this can do the job!


This method may get quite messy but it’s worth the try! Before starting, ensure that the water is turned off at the mains. Don on your gloves and look into the P-trap. 

The P-trap is located in the U-shaped pipe under your sink wherein you’ll find connectors on either ends. Put a bucket just beneath it and with the use of a pipe wrench, dismantle the connectors. A pipe wrench is especially required if it’s metal, but if it’s just made of plastic, a firm grip may do the trick. Then, pull the P-trap away and allow the bucket to collect the fluid. If there are accessible obstructions or clog, remove them. Run some cold water through the water to furtherly eradicate remaining debris. Once cleared, put the connectors back and run your water until it’s clear.

Composting coffee grounds

Composting coffee grounds and using them as fertilizers is a great way to not have your grounds end up in the sink where they will clog your pores or in the trash where they will just be added waste the environment. Just keep in mind that throwing in coffee grounds to the soil without composting them will just encourage mold. You may check your district if it runs a community composting service or a biomass boiler.

When added to citrus peels, especially from oranges, can repel cats from leaving litters all over your garden. Also, dried coffee grounds can repel insects and other pests in your garden.

You may also try using coffee grounds in your flower beds. They work especially well in acid-loving plants such as camellias, roses, and rhododendrons. Add some additional lime and wood ash to the mix and watch your flowers blossom and bear fruit beautifully.

To add on to our list, five and half pounds of coffee grounds can help you grow your own mushrooms. Think oysters and shitake! Spray the grounds with water and place them on a bucket or grow bag. Add in about a pound of mushroom spore and a few sawdust, then stir! Cut four small holes if your bucket has a lid. On the other hand, if you have an open container, cover with plastic and poke some holes. Moisten the grounds once a day and watch small mushrooms bud before your eyes in about a couple to four weeks. Once this happens, move the container to an area that’s lighter and with fresher air. You’ll know it’s harvest time once the mushrooms are plump and upward-turned caps.

Other uses of coffee grounds

  • Skin exfoliant
  • Hair rinses
  • Dye
  • Flea remover
  • Composite
  • Mosquito repellent

Find more things you can do with leftover coffee

Final words

We hope this article spoke volumes to you on why you should not flush your used coffee grounds in the sink. There are other better ways to reuse these! Let’s all keep our pipes clog-free!

Leave a Reply


Self-proclaimed coffee drinker. I would, on a typical day, start my day by grinding my coffee with a manual grinder and use a French Press as a starter (2 cups), then a pour-over in the afternoon (4 cups). I had my fair share as a barista but I prefer to drink it, not serve it.