Coffee Filter Sizes, Types, & Shapes You Should Know About

Like all things coffee, what is originally thought to be quite simple (whether that’s roasting, grinding, or brewing), is quite complex and has a tremendous impact on the entire process of making a great cup of coffee. The simple (or is it?) coffee filter can be included in this category.

Most people have an image of a paper coffee filtered, but to the trained eye, what appears to just be a coffee filter is actually a bleached, bucket filter that’s primarily used for average coffeemakers.

Between types of coffee filter sizes, shapes, different materials among other factors, it can be overwhelming to understand how these subtle differences, but fret not, our article will help you guide you along and learn to understand the differences and how these differences can impact the overall coffee brewing experience.

Coffee Filter Shapes

Generally speaking, there are three main “shapes” of coffee filters: conical filters, bucket filters, and disc filters. All of these “shapes” tend to be used based upon the type of coffee brewer used. The most commercially used coffee filters that most people are familiar with are the bucket and conical filters. Both tend to be used for most home and commercial coffee brewers so we will start there and then proceed to breakdown the differences between them all.

Conical Filters

As you could probably guess with the name, conical coffee filters form a cone shape. Starting with a wide opening that then gradually tapers to a fine point. These types of coffee filters are used from home drip coffeemakers as well as pour-over coffee systems. Additionally, conical filters are organized in four standard sizes based upon the volume that your coffee maker produces.

Coffee Filter Sizes

  • #1 Coffee Filters: This size is suited for one cup coffeemakers or pour-over systems
  • #2 Coffee Filters: This size is used for two-to-six cup coffeemakers/one-to-two cup pour overs
  • #4 Coffee Filters: This size is made for eight-to-ten cup coffeemakers or pour-over systems
  • #6 Coffee Filters: The size is aimed for large, ten+ cup coffeemakers

Bucket Filters

Bucket coffee filters (sometimes called basket filters) can be mainly found in most traditional home coffeemakers unlike its conical cousin, the bucket filter possesses a wide mouth and a wide flat bottom, however, due to their size, it can lead to coffee that can be uneven or under extraction and negatively affect the flavor of your morning coffee.

Disc Filters

Disc coffee filters can be predominantly be found in Aeropress coffee makers or other percolator coffee makers such as the French Press. At Coffee Bean Corral, we have replacement disc filters for the Aeropress as well. All this being said, it should be noted that these types of coffee filters should be used with medium-coarse to medium ground coffee.

Types of Coffee Filters

Broadly speaking, there are two types of coffee filters, paper (sometimes called disposable) and permanent. It is the type of materials that make up the coffee filter are the most important aspect and can truly affect the coffee bean’s flavor qualities during the brewing process; from under extraction, soaking up coffee’s flavorful oils, to environmental concerns with each have their idiosyncrasies and quirks within them that we’ll break down further

Permanent Filters

Permanent Filters fall into two distinct categories: metal and reusable. Both are great options for the environmentally friendly coffee connoisseur who wants to cut down on waste while brewing their morning cup of coffee.

Metal

Of the two permanent coffee filters, metal filters are made of steel or a similar type of often used. This type of coffee filter has a few pros and cons. Firstly, they cut down on paper and produce less waste than disposable coffee filters, however, they are usually found in pour-over coffee brewers, which limits their potential uses in other coffee brewers.

Additionally, they are not biodegradable and if not properly cleaned thoroughly small particulates and other coffee grime can accumulate and negatively affect your freshly brewed coffee’s taste. Luckily, Coffee Bean Corral offers a wide range of cleaning products to help clean away the coffee grime, helping your maintain your metal filter’s shelf life and continue to brew flavor coffee all year round.

Reusable

The other type of “permanent” coffee filter that can be found is a cloth coffee filter. These types of coffee filters tend to be a bit rare (at least in North America). Usually, this type is made from finely weaved fibers that act a sieve, catching any coffee grounds (even from fine grinds) and do not absorb the coffee’s natural oils as quickly as others.

Reusable cloth filters do require some care, so be sure to thoroughly wash the cloth filter between every use. Also, be mindful that they should not dry out too much nor remain damp between uses as this can leave off-flavors. Generally, these types of filters are reusable up to around 100 brews before the accumulation of micro-grounds, and coffee oils will begin to impart flavor to your coffee as well.

Paper Filters

Paper coffee filters are the most used type of coffee filter due to their affordability and ease of use. They are disposable, yet biodegradable, while at the same time do produce excess waste if not composed and just thrown them into the trash bin. Paper filters come into two types of options: bleached and unbleached.

Bleached

Generally, paper coffee filters are either bleached with oxygen or chlorine, and (luckily) most of today’s coffee filters are oxygen bleached. Doing so, allows the paper filter to catch finer particles which leaves you with a smooth tasting cup free from grounds. The trade-off is that the bleached paper filter absorbs the coffee ground’s natural oils and leaves you with a weaker tasting cup overall. An easy way to tell if a paper coffee filtered is bleached is by its white color.

Unbleached

Just as the name describes, unbleached coffee filters are just that. Generally, they are not as white as bleached filters, however, because of due to its lack of processing, this can give a papery taste on top of an already weakened cup of coffee. A good idea to help alleviate that is to wash them before usage. You can wash them by pouring hot water over the filter before brewing.

FAQs & Other Concerns

Do Certain Types of Coffee Filters Affect Taste?

Yes, as noted above different coffee filters can affect the taste of one’s coffee. The importance of this depends on you and your preferred brewing method, but by illustrating the differences, we hope to have cleared any confusion about which coffee filter should be used.

Do Coffee Filters “Go Bad”?

In a sense no but on the other hand, yes, coffee filters can “go bad”. Again, this depends on the type of coffee filter you are using. Paper filters will not go bad, but it is not wise to reuse them.

Whereas metal filters can be used indefinitely if properly cleaned and cared for. Meanwhile, cloth filters only “go bad” after a certain number of brews. In short, the answer is it depends.

Can You Compose Your Used Coffee Filter?

Yes, you can compose not only your coffee filter (if it is a paper coffee filter that is) but coffee grounds as well. Coffee filters and the grounds they contain make great compost. Rather than throwing them away after brewing, you can add them to your compost pile. They will break down faster if “buried” in between layers rather than if left to dry out on top of the compost pile.

What Can be Used as a Substitute When I Do Not Have a Coffee Filter?

Lots of things to be frank; toilet paper, muslin cloth, a fine sieve, paper towels, and even cotton socks can be used in a pinch as coffee filters.

However, we do not recommend any of these substitutes as they are neither designed to be coffee filters and would severely impact the overall quality of the brewed coffee.

As you now see, there is a significant range and variety of coffee filters. From the coffee filter size to the material it is made from. Each has its advantages and disadvantages and can affect the result while brewing coffee. Depending on your preference, we hope that this guide helped illuminate why those differences matter and how to help assist you in brewing up a cup of coffee just the way you like.