7 Things You Should Never Throw Down the Kitchen Drain

When you are working in the kitchen, most of the time, the sink becomes your go-to rubbish bin. You may not even give a thought to what you are throwing when you are rushing to prepare ingredients or too busy cooking different dishes.

Although this may be the fastest and most convenient way for you to keep the kitchen clean as you work on your dishes, you are not doing your garbage disposal and plumbing system any good when you throw just anything down the kitchen drain. Some items can block your drain and cause a variety of plumbing issues.

To avoid dealing with a blocked drain and other related plumbing problems,professional providers of plumbing services from Melbourne share below a list of items you should never throw down the sink:

1.    Fats, oil, and grease

These three items are the worst culprits behind blocked kitchen drains. When you pour these fatty liquids down the drain, they build up layers over the blades of your garbage grinder. Over time, they solidify and block the drain.

To properly dispose of fats, oil, and grease, put them in a container. Let them cool down first before throwing them in the rubbish bin.

2.    Foods that expand when wet

Throwing leftover foods that swell with water such as pasta, rice, potatoes, and beans in the kitchen sink can lead to a blocked drain. This is because these items will be continuously doused in water. They will soon turn into something with a paste-like consistency that will eventually obstruct the drain pipe.

It is best to throw these items in the bin as well.

3.    Fruit and vegetable peels and their stickers

The peels or rinds of apples, bananas, potatoes, and tomatoes can easily block kitchen drains as well. These rinds can become paste-like substances over time as well and end up blocking the drain.

Aside from peels, make sure you don’t throw produce stickers in the sink. Even if they are small, these stickers can get washed off and get stuck in your drain, pipes, filters, and hoses.

To prevent stickers from accidentally going down the drain, use a strainer when washing produce or manually remove them from the fruits and veggies.

4.    Eggshells

If you don’t have a garbage disposal unit, never throw eggshells in the sink. Even the smallest pieces can easily cause an obstruction in your pipes.

Many people say that putting eggshells down the garbage disposal is actually beneficial since they can help sharpen the blades and even enhance the performance of the machine. However, eggshells are also rough and abrasive; as such, they can also blunt the blades.

It is best to throw eggshells in a bin or collect them to make compost.

5.    Coffee grounds

A lot of people dispose of coffee grounds down the sink they believe the rumor that the coffee grounds’ acidic and graining texture can clean drains. However, there is no truth to this since coffee grounds are only acidic when they are fresh. Once used, they become neutral and will only build up in the pipes.

Aside from tossing your used grounds in the bin, you can use them as fertilisers. There are other uses for them as well which you can read about on the Internet.

6.    Flour

When flour is mixed with water, you get a paste-like, gloopy mess. You will also get the same result when you throw flour down the drain, which will accumulate and cause a messy buildup in your pipes.

To prevent the combination of water and flour from blocking your drain, throw any used or unused excess in the bin.

7.    Bones

Lastly, fish bones are safe to throw down the drain. However, even if you have the most efficient garbage disposal system, it won’t be any match for poultry or meat bones.

This is because bones from fowl and larger animals will make blades blunt and weaken the machine’s mechanics. The garbage disposal won’t break down bones completely as well and as a result, they will block the pipes and prevent other liquid from filtering through.

Additionally, the bones will cause the machine to start working less efficiently in the long run.

Knowing which items you can throw down the sink is a good start to keeping your drains and plumbing system working properly. Pouring boiling water down the drain once a week will prevent blockage-causing build-up on the interior surface of pipes as well. As such, don’t forget to include this in your list of regular kitchen cleaning chores.

In case you notice that your kitchen sink drain isn’t working properly even after trying the usual DIY drain cleaning and unblocking tips, call a plumber to check your pipes and fix your plumbing issue immediately.


Based in South Melbourne, Blue Diamond Plumbing was founded in 1985, working on new homes, repairs and commercial contracts. Over time they have grown to become some of the best plumbers Melbourne has to offer. Since 2001 the company has specialised in Emergency Plumbing and Property Maintenance, Repairs and Renovations for homes and businesses in Melbourne and inner city suburbs. Owner Rod Diamond has over 30 years’ experience with emergency plumbing in Melbourne’s inner suburbs.