Used coffee grounds and coffee leftovers usually stink with time and can be dirty and messy. They can be one of the biggest problems for cafes and restaurants that serve coffee. Not only that, but they also block the portafilter with time. That’s why it’s critical to get rid of them as soon as possible. The best to do that is by using a coffee knock box! So what is a coffee knock box?
A coffee knock box is a small bin you put used coffee grinds in. It’s called a knock box because you literally knock the coffee grounds out of the filter into the box. This prevents you from making a mess in your kitchen or your normal trash bin. It’s also a great way to collect used grounds for composting.
So how can a coffee knock box benefit you? Read on if you want to know everything about coffee knock boxes. So without further ado, let’s dive in!
What Is a Coffee Knock Box?
The traditional way of cleaning the coffee filter is by scooping all the spent and depleted coffee grounds out of the filter then giving it a nice rinse to completely get rid of all elements of coffee that are stuck to them.
The problem is, scooping and emptying the spent coffee grounds can be quite inconvenient using the traditional way.
This is because the spent coffee grounds will usually retain some wetness that enables them to get easily stuck to the bottom of the filter, so they become very difficult to scoop out.
Not to mention that they can be extremely hot if they’re just pressed into espresso. This led to the invention of the coffee knock box.
What Does a Knock Box Do?

It’s a small and simple bin-shaped device that you can use to conveniently get rid of spent coffee grounds and leftovers with ease to save time and effort.
Author Note: It’s mainly known as the knock box because you literally knock the coffee grounds from the portafilter directly into its bucket part once it’s full of coffee grounds, hence the name.
By knocking the filter into it, the coffee grounds are dislodged into the knock box, leaving the filter clean in seconds!
In addition to coffee knock box, it’s also informally known as “bang bin”, “bash bin”, “slam piece”, and “coffee column”, which all carry the same meaning.
The Design of a Coffee Knock
Despite being a relatively simple design, every part of the coffee knock box is very essential for its functionality.
Coffee knock boxes’ bodies can be made from a wide variety of materials, including plastic, wood, and stainless steel. It’s usually made from rather sturdy materials to handle the continuous knocking and bashing.
In addition to the body of the box, It usually has a durable bar in the middle known as the “bash bar”, which you tap the portafilter filled with espresso spent beans into.
Since this part is subjected to frequent tapping and knocking to dislodge the hot espresso remains and spent grounds, it’s mostly made of rubber.
Types of Knock Boxes
Now that you know what coffee knock boxes are, it’s time to know more about the types of coffee knock boxes on the market.
Since the design of a coffee knock box is super simple, they vary in terms of materials used in construction as well as design styles. Let’s have a look at some of the types and materials involved in the construction of knock boxes.
Simple Plastic Knock Boxes
Plastic knock boxes are the most affordable ones on the market and they’re usually available in different colors and styles because they’re easy to shape.
Being plastic doesn’t mean they’re weak. However, they’re definitely not the strongest material either.
They’re lightweight and easy to use, which makes them ideal for daily family use, which average use when compared to cafes and coffee shops.
Simple Stainless Steel Knock Boxes
Although stainless steel knock boxes are a little more expensive than the average plastic knock box, they’re still more commonly used in cafes as well as households.
Simple stainless steel knock boxes can be made into a square and round bucket styles. The round stainless steel knock boxes are usually designed with the same style as the plastic ones.
The only difference is that they offer more durability and can be made into bigger knock boxes without compromising their sturdiness.
Moreover, stainless steel usually looks much better and more professional when compared to plastic, which is why a lot of hardcore coffee connoisseurs prefer them over plastic ones.
On the other hand, the square-shaped knock boxes don’t offer an ergonomic advantage, but they’re often easier to fit in wooden boxes and tables for aesthetics and less visual clutter.
Some knock boxes are even sold with a ready-made wooden box. These ones are often quite large and more expensive than the round ones. However, it’s not likely to need a large one if you’re only using it in your house or office.
Drawer-Style Knock Boxes

These knock boxes completely stand out in terms of design, as they’re flat rectangular boxes that have a built-in drawer.
They’re usually designed to fit under an espresso machine or a coffee grinder where you pull the drawer whenever you need to get rid of a new patch of coffee grounds.
These ones are usually exclusive to professional users, such as baristas and coffee shops in general.
Author Note: They’re significantly more expensive and can easily grow molds if you don’t clean them on a regular basis because the drawer design limits their airflow and ventilation.
The Benefits of Having a Coffee Knock Box
If you’re an avid coffee consumer who makes their own espresso or drip coffee, you’ll definitely need one of those in your coffee making gear!
Let’s have a brief overview of all the reasons why you need a coffee knock box.
Convenient Way to Store Coffee Grounds
The knock box is designed specifically for that task, so it’ll prevent splashes of coffee ground and mess on your countertop while making coffee.
Easier to Clean
As you already know, caring for a coffee knock box is one of the reasons you should get one. Simply, the ideal way to care for a coffee knock box is by regularly cleaning it.
Make sure that you don’t leave the coffee grounds there to dry out completely because it’ll be quite difficult to toss them out with a few knocks.
To clean one, simply remove the knock bar and scoop out any remaining bits. After that give both the bucket and knock bar a quick rinse with warm water and dish soap.
Luckily, most coffee knock boxes out there are dishwasher-friendly, so you can even toss it in the dishwasher for hassle-free cleanup.
Save Time
If you make multiple patches of coffee, having a knock box will allow you to get your portafilter ready in seconds, which is much easier than scooping and rinsing the filter with every shot of espresso pulled.
Prevents the Foul Odor of Old Coffee Grounds

With convenient storage, you’ll be able to avoid the nasty odor of ground coffee remains, which can easily radiate out of the trash bin.
Coffee knock boxes are designed to trap the odor of coffee until you conveniently get rid of the grounds.
Ideal for Compost Gardens
Coffee grounds are great for dirty and smell awful. However, if you’re into composting, you’ll know how great they’re for the soil.
Author Note: In fact, composting the coffee grounds will save you the hassle of dealing with coffee ground trash and help you supply your garden with excellent nutrition!
How to Make Your Own Coffee Knock Box
Although a knock box is usually affordable, you can make your own wooden knock box if you enjoy DIY projects.
This DIY guide shows you how to make one easily. Keep in mind that despite being easy to build, it requires some table saw handling and carpentry skills.
How to Use a Coffee Knock Box
Using the coffee knock box is surprisingly easy, as there are no settings to choose from or buttons to press.
After you’ve successfully pulled the espresso out of your portafilter, simply knock the portafilter exactly in the middle of the knock bar 3 to 4 times.
Make sure that you hold your knock box, especially if it’s made of plastic, to prevent it from tipping over while being knocked.
The taps should be firm but gentle, which are usually enough to expel the spent coffee grounds into the bucket.
Top Coffee Knock Box Options on the Market
While shopping for a coffee knock box, there are some aspects and points that you need to keep in mind.
For example, If you don’t have to deal with coffee grounds that much, you don’t have to spend more money for an extra durable stainless steel knock box.
In that case, you can invest in a plastic one that will also be quite easy to deal with, such as Dreamfarm Grindenstein Bin.
If you want an all-around better coffee knock box, you might want to consider a stainless steel coffee knock box, such as the DeLonghi DLSC059 Accessory.
Wrap Up
With that said, you now have a better idea about what a coffee knock box is and how it can benefit you, especially if you have a backyard garden.
As you know, some knock boxes are more expensive than the other. For example, if you’re on a strict budget, you should opt for a simple plastic knock box. This one will get the job done without breaking the bank.
However, if you’re a professional barista who wants the most convenient style no matter the price, the drawer coffee knock box will work best for you.
Stay caffeinated friends!