Can You Put Coffee Grounds Down the Garbage Disposal?

The garbage disposal often seems like the perfect way to get rid of any and all food waste. However, it is essential to be careful with what items you are putting down there. The wrong things can lead to clogged drains, ruined garbage disposal systems, and high plumber costs. Therefore, before tossing food waste down the drain, it is essential to do your research first.

You should never put coffee grounds down the garbage disposal. Instead of breaking down, they clump together when exposed to water and also attract grease. This leads to a build-up on the sides of the drain pipes. Over time, this will cause a clogged drain that smells of coffee.

In this article, I’ll explain why you shouldn’t put coffee grounds down the garbage disposal in more detail.

I’ll also discuss whether or not you can dispose of grounds in a sink drain, toilet, or septic system and why or why not. Plus, I’ll provide you with information on how to dispose of coffee grounds and other items that should not be put down in a garbage disposal.

Why Coffee Grounds Should Not Be Put Down the Garbage Disposal

Putting coffee grounds down your garbage disposal should be avoided, as this will result in a jammed or clogged garbage disposal system. In addition, over time, coffee grounds in garbage disposals are a recipe for disaster.

The main reasons for this include:

• The grounds settle between the impellers of the garbage disposal system. The impellers help break the food waste down into smaller particles. Clogged impellers will prevent them from adequately disposing of other items you put down in the garbage disposal.
• Coffee grounds attract grease. The combination of grease and coffee grounds creates a sludge-like substance that builds up in your pipes and attaches to the garbage disposal system, resulting in clogs.
• Grounds also clump together when exposed to warm and room temperature water. Like with grease, this makes it easier for the grounds to stick to your pipe drains, causing a build-up and clogs.

Given the problems that putting coffee grounds in your garbage disposal can cause, it is always best to look for other disposal methods, like the ones I’ll discuss further in the article.

However, if you find yourself in a situation where garbage disposal is your only option, make sure to flush them thoroughly before you do so.

Tossing grounds down the disposal once in a while shouldn’t be an issue. However, if you make it a habit, expect to be facing down significant plumbing bills sooner or later.

Can You Put Coffee Grounds Down the Sink?

You should not put coffee grounds down the sink because the grounds will get stuck in the sink pipe’s U-bend. Over time, a build-up of grounds can cause your sink to drain slowly or back up altogether, and a plumber may be required to fix the problem.

Even if your sink doesn’t have a garbage disposal, coffee grounds still have the same issues that make disposing of them through the garbage disposal an unwise option.

If you do choose to rinse your grounds down your sink, you can expect to have to call a plumber sooner than you expect.

Theoretically, the garbage disposal is a better option for coffee ground removal than a sink, as the disposal might break the grounds down a little further, increasing the chances of passing through without an issue. You don’t have this advantage with a standard sink.

Toilets

As with sinks, flushing coffee grounds down your toilet can create a clogging issue.

Remember, the drainage system to and from your toilet involves a system of pipes. Like with sinks, there is always a risk that the grounds will accumulate in these pipes, causing clogging.

Additionally, as mentioned, coffee grounds tend to attract oils and other food materials. These will stick to the grounds already trapped in the drainage system and increase the size of the clogging.

While flushing coffee grounds down the toilet once shouldn’t cause much of a problem, doing so repeatedly will only increase the risk of backed-up and damaged toilets and drainage systems.

Septic Systems

If you’ve got a septic system or tank, it is natural to think that coffee grounds can be disposed of via this system. However, as with the previously mentioned methods, grounds should never be put into a septic system.

There are two significant reasons why septic systems shouldn’t be used to dispose of coffee grounds.

The first reason is simple – coffee grounds cannot be effectively broken down and decomposed in a septic tank. This means that (like other non-decomposed solids) the grounds will settle at the bottom of the tank, collecting and creating a layer of semi-solid sludge.

This layer will have to be removed by a professional, which can be expensive. Also, the more coffee grounds that go into the septic system, the faster this will become an issue. This is also why you cannot put items like tampons and other feminine hygiene products into the septic system.

The other reason that coffee grounds in your septic system can cause a problem has to do with the system’s pH balance.

For a septic system to function efficiently, it needs an ecosystem that allows bacteria to thrive. These bacteria then feed on the waste in the system, helping speed decomposition.

The bacteria in a septic system need a relatively neutral pH environment to live in and do best when the pH is between 6.5 and 7.5.

Brewed coffee, on the other hand, has a much lower pH. Its pH ranges from 4.5 to 6.0, depending on various factors such as the type of coffee and method of brewing, which is too acidic for the bacteria to live in.

When coffee grounds enter the septic system, the coffee brewing process essentially starts again. This isn’t to say your system will effectively become a massive cup of coffee.

However, chemicals will leach out of the grounds and acidify the environment around them just like they would to the water in a coffee pot.

As with most other options, a few stray grounds won’t make much of a difference to the larger environment to cause an issue.

However, suppose you are constantly disposing of coffee grounds into your septic system. In that case, there is a risk that the grounds will accumulate in the tank and create a space that’s too acidic for bacteria to live in.

This, in turn, means that your septic system will no longer be able to do its job. As a result, nothing in the septic tank will decompose as it should, which can’t only ruin the tank but also cause an awful smell in and around your property.

How To Dispose of Coffee Grounds

While your garbage disposal, sink, toilet, and septic system are out of the running, this doesn’t mean you don’t have options when it comes to getting rid of your old coffee grounds. 

How do you dispose of coffee grounds? There are numerous ways you can get rid of them, including:

Toss Coffee Grounds in the Trash

While tossing coffee grounds down the garbage disposal can cause issues, you can easily throw the grounds out in your trash can without any problems. Indeed, this is how most people get rid of the old grounds, and it is the easiest and fastest solution available to you.

Reuse Coffee Grounds as an Odor Remover

People put coffee grounds down their drains and garbage disposals because they believe that doing so will help eliminate unpleasant odors. And while this may be true, the negatives mentioned above far outweigh this positive.

However, you can use these odor-eliminating abilities to your advantage when cooking with aromatic ingredients like onion and garlic.

Also, rubbing your hands with coffee grounds before rinsing with water can help eliminate any lingering smell that may be present on your skin even after you’ve washed it with soap.

Use Coffee Grounds in Composting and Gardening

Coffee grounds make for excellent fertilizer, and adding them to your compost pit is one of the best ways to get rid of the grounds without tossing them in the bin. 

As a fertilizer, the grounds are rich in essential nutrients that can boost plant growth, including iron, magnesium, and calcium. Additionally, they can absorb some metals from the soil, which would otherwise hinder plant growth.

Furthermore, coffee grounds can help boost the nitrogen content of compost, which is an essential requirement to speed up the breakdown of plant matter.

More than that, as mentioned above, they help create an acidic environment, which earthworms (another integral part of most compost piles) love.

Coffee grounds can serve as an effective (and natural!) pest repellent when it comes to gardening. They help keep away various common critters, including snails, slugs, and other harmful insects. They’re so effective that they can even repel certain types of cats and rabbits.

Repurpose Coffee Grounds as Cat Repellent

As mentioned above, coffee grounds can serve as an effective, natural cat repellent. If you’ve got a cat problem in your backyard, or if your neighbor’s cat simply won’t keep to its own home, sprinkling the ground with coffee grounds can help solve your problem in no time.

You may also find it an effective solution to preventing your own cat from leaving your home. If you’ve got an inside cat that’s trying to get out, especially when you are away from home, coffee grounds are an easy trick to ensure your cats stay safe in your home.

Create a Beauty Scrub Using Coffee Grounds

You read that right – coffee grounds can actually help your skin look better! In addition, these grounds can help make both face and skin scrubs.

Mixing coffee grounds with some coconut oil creates an effective face scrub. Adding grounds to a basic salt scrub and coconut oil recipe will help make a skin scrub that will help you get rid of rough skin.

Additionally, the caffeine in the grounds will help brighten your skin, giving you a fresh, glowing complexion.

Make Arts and Crafts Materials With Coffee Grounds

Coffee grounds can also be used in various arts and crafts projects around the home. For example, if you make your own modeling clay at home (whether for personal use or to keep your children entertained), adding coffee grounds to the recipe can help create dark brown clay. 

Additionally, you can brew the grounds to create a dye bath. You can then use this bath to dye fabrics or Easter eggs or as a natural watercolor paint. 

Alternatively, if you want to dye fabrics with coffee grounds, you massage the grounds into the material in question. To do so, first, create a paste with the grounds, and smear the same on the fabric. Next, let the fabric dry completely, and then brush off any excess grounds still on the material.

What Not To Put Down the Garbage Disposal

Coffee grounds aren’t the only thing to avoid putting down the garbage disposal. Here are several other everyday items for which you need an alternative disposal method:

Oils and Grease

If you are cooking with oil or draining grease (from food items like meat, bacon, gravy, etc.), you should never pour the excess liquid down your garbage disposal or your sink.

Oils and grease will quickly thicken in the pipes and create major clogs, and you’ll likely need professional help to remove them from the system.

Eggshells

You may have heard the urban legend that putting eggshells down the garbage disposal can sharpen the disposal system’s blades. However, this couldn’t be further from the truth.

Like coffee grounds, eggshells are sedimentary in nature and trap other, drain-safe items that you may put down the drain.

If there are too many shells put down in the disposal system, you risk creating a build-up. This, in turn, will either result in a significant clog or a “slow drain” situation, in which only small items still go through the system.

Additionally, there is a risk that the eggshell membranes will get wrapped around the motors in your garbage disposal system. This can result in the membranes splattering all over the system’s walls and increasing the risk of a clogged drain.

Pasta and Rice

The reason these food products should never be put down in the garbage disposal is simple – they expand when exposed to water.

Think back to when you have cooked with pasta or rice. While they’re small and easily packaged in their pre-cooked state, they expand significantly when you put them in hot water.

This process also takes place when they’ve put down a drain or a garbage disposal system. After all, you don’t just put food items down these systems; you also run water down them.

Thus, when the rice or pasta expands in the pipes, they block the passage of other items, creating a significant clog in the system.

Additionally, rice doesn’t just become bigger; it also turns into a dense, starchy substance that clogs all the more readily. Instead of using the garbage disposal or sink to get rid of them, you should dispose of them in the trash.

Paint

If you’ve got old paint in your home, it should always be disposed of as hazardous waste rather than down the drain. This remains true regardless of whether the paint in question is oil-based or water-based.

When poured down the garbage disposal, the paint will stick to the walls of pipes and prevent other items from going down smoothly.

At the same time, it shouldn’t be disposed of with regular waste. Instead, contact your city or garbage collector to check about paint disposal and hazardous waste pickup.

Fruit Pits and Avocado Seeds

None of those mentioned above items should go down a garbage disposal system. Instead, you can toss them in your composting pit or throw them in the bin alongside other “wet waste.”

This is because these items are extremely hard and may damage the blades of your garbage disposal.

Even if your disposal system manages to break them down to a manageable size, there is a risk that the pits and seeds will have done their share of damage as well, as that you’ll have to spend a lot of money on repairs.

Final Thoughts

While your garbage disposal system may seem like the perfect way to get rid of old coffee grounds, it is essential to make sure you choose other ways to dispose of them instead. When putting down the garbage disposal or the sink, coffee grounds can quickly create a blockage that will be expensive.

Instead, use the grounds in your compost pile to create homemade beauty scrubs, as a cat repellent and odor remover, and more. Alternatively, you can even toss it in with the rest of the trash if other alternatives are too labor-intensive.