Understanding Coffee Filter Sizes, Types, and Shapes

When it comes to brewing coffee, most of the care goes into selecting the best coffee beans, the best coffee maker, and the perfect grind size. Coffee filters are something we take for granted, meaning that they don’t get as much love as the other components of the brewing process.

What if we told you that choosing the right coffee filter also plays a huge role in how your brew turns out? After all, the filter is responsible for what ends up in your coffee, and what doesn’t. By choosing the correct filter, you will be taking your coffee game to the next level.

Unfortunately, there is no magical way to know which filter would suit you the best, and with so many varieties of filters to choose from, it could get confusing very quickly. For this reason, we have prepared an extensive guide to help you understand the differences between different filter sizes, types, and shapes in hopes of getting you one step closer to coffee perfection.

If you’re feeling ready, let’s dive in.

How Does a Coffee Filter Work?

To understand how we could make use of different filters to improve our brew, we first need to understand how coffee filters work. While a coffee filter plays an important role, this role is very simple to understand.

When hot water comes into contact with coffee grounds, the flavor components of the grounds are absorbed by water, creating coffee. Since we have no use for the coffee grounds after this process is over, we need to separate liquid coffee from the coffee grounds. 

The coffee filter comes into play at this point, allowing the liquid to pass through while trapping the grounds and other undesirable particles we wouldn’t want in our drink. The extent of filtering depends on the type of coffee filter, which we will be covering in the section where we go over different types of coffee filters.

How Should I Use a Coffee Filter?

The usage of a coffee filter depends on the brewing method, but it’s pretty straightforward regardless as the task of the filter remains unchanged.

Let’s go over some common brewing methods and the proper way to use a coffee filter with them.

Automatic Coffee Makers

Automatic coffee makers usually utilize a filter basket where coffee grounds are supposed to be placed. 

All you have to do is to insert the coffee filter in the filter basket, and then add the coffee grounds inside the filter.

Aeropress

Aeropress utilizes a disk coffee filter that fits into the filter cap. 

Simply place the filter into the filter cap before screwing the filter cap onto the chamber.

Chemex

Chemex paper filters can prove to be confusing to use if it’s your first time as they come in the form of sheets of paper.

To be able to use these filters, you will first have to fold them into a cone. The folded filter will fit nicely into the Chemex.

If you decided to use a metal filter instead, you can simply insert the filter in the Chemex as they already come in the form of a cone.

Hario V60

Hario V60 utilizes a special cone filter that is specifically designed for it.

All you have to do is to make sure that the filter is tightly fit into the Hario V60.

French Press

French presses utilize disk coffee filters that go between the plunger and the beaker. While metal filters are more popular in the case of the french press, it’s entirely possible to use paper filters as well.

Generally, the filter is attached to a plate at the bottom of the plunger which you can unscrew to replace the filter.

Percolator

Percolators also use disk filters, and they are fairly easy to use.

The disk filter easily fits into the filter by putting the hole of the filter through the perk (the tube which sticks out of the filter basket) tube.

Coffee Filter Types

The type of a coffee filter is determined by the material it’s made of, and for the most part, you’ll find that coffee filters are either paper, cloth, or metal. 

Since each of these materials have different characteristics, the way they filter coffee is also different, meaning that the type of your coffee filter impacts the taste and feel of your coffee directly.

Paper Coffee Filters

Paper coffee filters are the most common type of coffee filter, available in almost every shape, for every brewing method. While different brewing methods utilize different shapes and sizes of paper filters, you should easily be able to find a compatible paper filter for the brewing method of your choice.

These filters are considered to produce the purest, most acidic coffee possible as they trap everything other than the coffee liquid, meaning that none of the unwanted particles or coffee oils can pass through. While this sounds like the best scenario possible, the trapping of coffee oils means that the entire flavor profile of the grounds isn’t transferred to your brew. 

Since paper filters aren’t reusable, they usually come in boxes that contain a large number of them. Ensuring that you use a fresh filter for a fresh brew will provide the best results as a paper filter usually loses its integrity as soon as it’s used.

Bleached vs Unbleached Coffee Filters

You might’ve noticed that some paper coffee filters are white, and some are brown. As you know, the natural color of paper is brown, and the white color is attained by a process called bleaching.

This process can either be done with chlorine or oxygen, with filters bleached with oxygen being considered to be of higher quality. If you’re considering using bleached coffee filters, it’s a good idea to keep an eye out for a label that mentions oxygen.

Bleaching doesn’t make a huge difference in terms of your coffee experience, but it sometimes helps to get rid of the paper taste caused by the filter. On the other hand, unbleached filters are considered to be environmentally friendlier.

If you decided to go with an unbleached filter and have trouble with the paper taste, a quick trick that may help is to rinse your filter with hot water once or twice. You can achieve this by placing your filter in your coffee maker, pouring water into the filter, and then discarding the water.

Metal Coffee Filters

Just like paper coffee filters, it’s possible to find metal coffee filters in various shapes and sizes as well, depending on the brewing method you’re using. While not as common as paper coffee filters, metal coffee filters bring a different set of characteristics to the table.

The main difference which separates a metal coffee filter from a paper coffee filter is the difference in the size of the pores. Since metal filters utilize a mesh for the filtering process, the pores are bigger in comparison to a paper filter, allowing finer particles and oils to go through. 

Even though this may sound like a bad thing when you first think about it, the fine particles aren’t noticeable since they are too small, and the oils add a new level of flavor to the drink by increasing sweetness and reducing acidity.

Cleaning

Metal coffee filters are designed to be reused, meaning that you will have to clean them. Luckily, they are very easy to clean with the right tools. 

Let’s quickly go over the steps which will ensure that your coffee filter is clean and good to go for the next brew.

  1. Start by throwing the used coffee grounds into the trash. You will be able to get rid of most of the grounds this way, but some grounds will be stuck in the holes.
  2. With the help of a fine brush, get rid of the coffee grounds that are stuck in the holes. You should be able to get rid of all the grounds within a few minutes of scrubbing.
  3. Wash the filter thoroughly with water and soap. 
  4. Leave the filter out to dry.

While it may seem like a lot of work to wash the filter every day, it won’t take more than a few minutes of your time.

Cloth Coffee Filters

Even though they are the least popular option out of the three, cloth coffee filters also have their uses, and it’s possible to find them in different shapes and sizes just like paper and metal coffee filters.

When it comes to taste and feel, cloth coffee filters arguably provide the best experience. These filters do an excellent job when it comes to trapping the coffee grounds while letting the coffee oils go through. This way, you don’t get any unwanted particles in your drink, and also get to enjoy the full flavor profile of the coffee.

On the flip side, the maintenance of a cloth coffee filter takes the most amount of work. They require a very thorough washing to get all the coffee grounds out and drying them also takes a considerable amount of time. On top of that, these filters slowly lose their integrity with each wash, meaning that you will eventually (around 100 uses) have to replace them.

Coffee Filter Shapes

Even though the shape of the coffee filter you should be using is largely determined by the brewing method, some brewing methods allow you to choose between different shapes, allowing you to customize your drink even further.

In this section we will be talking about the three different coffee filter shapes, the brewing methods which utilize them, and how they can impact your drink.

Basket Coffee Filters

When you think of coffee filters, a basket coffee filter is most likely the one that comes to mind. These filters are mostly used with automatic coffee makers as this shape of filter fits easily into the filter basket of an automatic coffee maker.

Basket coffee filters are very common as they are much cheaper than cone filters, and come in a larger size than most. On the flip side, they have slowly been going out of fashion in favor of cone filters as these filters don’t do the greatest job when it comes to extracting the coffee grounds.

This problem is caused by the flat-bottomed shape of basket filters which cause the grounds to be spread unevenly, preventing the water stream from hitting all of the grounds in an equal manner.

Cone Coffee Filters

Cone coffee filters can both be used in drip coffee makers and certain pour-over coffee makers such as Chemex and Hario V60.

Even though they are more expensive than basket coffee filters, coffee enthusiasts will often prefer them over basket filters even for their drip coffee makers as they do a much better job of extracting the coffee grounds.

The advantage of this filter comes from its conical shape which allows it to gather coffee grounds in a tightly packed form at the bottom of the filter. When water is poured, it has to go through all of the coffee grounds to pass the filter, creating a much better process where all the grounds are equally extracted. 

Disk Coffee Filters

Disk coffee filters are most commonly found in Aeropresses, french presses, and percolators. These filters are different from basket and cone filters in the sense that their size doesn’t have an impact on the amount of coffee brewed.

There isn’t much of a choice when it comes to disk coffee filters as they are the only option for these brewing methods.

Coffee Filter Sizes

Coffee filter sizes and the purpose of different sizings depend on the shape of the coffee filter, which is why we will be talking about sizes on three different subcategories that correspond to the different shapes of coffee filters.

Cone Coffee Filters

Between the three different shapes of coffee filters, cone coffee filters have the widest variety of sizes. Each of these sizes corresponds to a certain amount of cups depending on the brewing method used.

#1 Size Filter

No.1 is the smallest cone filter, suitable for a single cup of coffee with an electric coffee maker.

#2 Size Filter

No.2 filters are generally suitable for brewing either 2 to 6 cups with an electric coffee maker, or 1 cup with a non-electric coffee maker.

#4 Size Filter

No.4 is the most common cone filter size, suitable for brewing 8 to 12 cups with both an electric and a non-electric coffee maker.

#6 Size Filter

No.6 is the biggest cone filter, suitable for 10+ cups of coffee with both an electric and a non-electric coffee maker.

Basket Coffee Filters

Basket coffee filters come in two different sizes, which are standard and junior. 

The standard basket size is used for the most part, with junior size being preferred if less than 6 cups are brewed.

Disk Coffee Filters

Size works a bit differently when it comes to disk coffee filters since the size is mostly about the filter fitting the coffee machine rather than the amount of coffee being brewed.

These filters usually have a standard size of 3 to 3.5 inches as they are meant to be used with percolators and french presses.

Choosing the Right Coffee Filter

Now that we know how different sizes, types, and shapes of coffee filters are used, we can use this knowledge to choose the coffee filter that is the best fit.

Taste/Feel

When it comes to taste and feel, the biggest role is played by the type of coffee filter, with coffee filter shape playing a supporting role.

For those who enjoy a very pure coffee experience with no sediment and the full acidity of the coffee, paper filters are the definitive choice. We recommend going for unbleached paper filters as they are environmentally friendlier, and the paper taste problem (which bleached paper filters are supposed to solve) can be eliminated by rinsing the filter anyway.

Those who like their coffee with more body and aroma should lean towards cloth or metal filters instead. While cloth filters come with different disadvantages of their own, they are clearly the winner when it comes to mouthfeel as they do a much better job filtering unwanted particles compared to metal filters.

As for the shape, conical filters should always be preferred over basket filters for their ability to deliver a better extraction.

Cost

In terms of initial cost, metal coffee filters are the most expensive, followed by cloth filters and lastly paper filters.

That being said, a paper filter can only be used once, a cloth filter can be used for almost 100 uses, and a metal filter can be used for a lifetime if maintained well. For this reason, those who brew coffee very often will find the maximum cost efficiency in metal filters, while someone who doesn’t brew as often will get better value out of paper or cloth filters.

The shape of the coffee filter also impacts the price to a degree, with cone coffee filters being more expensive than basket coffee filters.

Maintenance

The last consideration is maintenance. Since paper filters are single-use, they are automatically the winners in this department.

Between cloth and metal coffee filters, metal filters are definitely easier to maintain. Washing a metal filter and clearing out the debris is fairly simple compared to having to wash all the coffee off of a cloth filter and drying it.

FAQ (Frequently Asked Questions)

Can my coffee filter go bad?

While cloth filters eventually become unusable after around 100 uses, a metal coffee filter can last you a lifetime with proper care.

Since paper filters are meant to be used only one time, there isn’t any room for them to go bad.

Can I reuse my coffee filters?

Reusing paper coffee filters aren’t recommended. If you’re looking for reusable alternatives, you should consider cloth or metal coffee filters instead.

What is the standard coffee filter size?

The standard coffee filter is 8 to 12 cups, which corresponds to the regular basket filter size, and #4 cone filter size. 

My coffee filter doesn’t fit my machine, what do I do?

If your filter is too big for your machine, you can trim the filter around the edges until it fits.

If your filter is too small for your machine, you might get away by adding a lesser amount of coffee grounds into the filter, but this isn’t a definitive solution.

Conclusion

With that, we conclude our journey to understanding coffee filters. 

We believe that it’s a topic every coffee drinker should be familiar with as it’s such an important piece of the coffee experience even though it’s overlooked for the most part.

Have a great day and enjoy your coffee!