Coffee Maker Filters: Does Your Machine Need One? Which Size To Use?

Do coffee makers need a filter

So you’re trying to brew a pot of coffee using your coffee machine, but not sure if you need a paper filter or not? Well, that will mostly depend on which machine you have and whether or not it includes a permanent filter.

What Does a Filter Do in a Coffee Machine? It Is Necessary?

Whether it’s a Mr Coffee, Hamilton Beach, Cuisinart or other brand of coffee maker, a filter – any type of filter – is an important part of the brewing process. The filter catches the coffee grounds so they don’t end up in the brewing pot, or worse in your cup. This is why it is important that you use a filter when making coffee.

When there is no filter – whether paper or permanent – used for a particular machine, then the grounds will make their way into the brew, making the coffee too strong and bitter. A filter also catches oils and sediments from coffee beans.

Do I Have To Use a Filter in My Coffee Machine?

To answer your original question, the answer is yes, you must use a filter when brewing coffee using a machine or a manual brewer. It’s just a matter of which type of filter you need to use So keep reading to understand the difference between filters and which is best for you.

Types of Coffee Filters (for Machines and manual brewers):

Paper vs Permanent coffee filter

Paper filters are the most common type of filter used in automatic drip coffee makers and pour-over tools . They come in all shapes and sizes, from flat bottom filters, to cone-shaped filters. The size of the filter you’ll need depends on the model and size of your machine –

Permanent filters are generally made from gold-plated stainless steel or nylon mesh. They have similar purposes as paper filters in that they help to keep grounds and oils out of the coffee. The difference is that permanent filters are designed to be used over and over again, so there is no need to replace them with a new one each time you make a pot of coffee.

Paper vs. Permanent – Which Is Best To Use?

It really is a matter of personal preference when it comes to deciding which type of filter you should use in your coffee machine. Many people prefer the taste of coffee brewed with paper filters because they absorb more oils and grounds than permanent ones do, making it less bitter.

On the other hand, others like to have a permanent filter on hand so that there is no need to go out and buy new filters each time. It also eliminates the need for disposing of old, used paper filters.


Of course, paper filters are easiest to manage when it comes to cleaning. Because you simply dispose of them after each use. You’ll still need to clean the filter basket that holds the paper filter, but that’s easiest part because you’ll dispose of the grounds in the paper filter and will only have to rinse out the filter basket.

A Permanent filter, on the other hand, is messier to clean. To start, you’ll have to get rid of the grounds in a bin (never dispose of ground in a drain, it will eventually clog it!). Then, you’ll have to wash both the permanent filter and basket. After a while of use, the mesh on permanent filters can get clogged, so make sure you really clean through the holes and ensure no grounds are clogging them.


Paper filters, although easiest to clean and dispose, are an ongoing cost. However, they are super cheap and in you can buy them bulk. So I wouldn’t worry much about the cost of paper filters.

But of course, with a permanent filter, you only buy it once. In fact, some coffee machine include one with your purchase.

Shape of Filter You Need

When it comes to coffee filters, either paper or permanent, there are two shapes: a cone filter or a flat bottom filter. Which one you choose will actually depend on your coffee machine model:

Cone vs. Flat Bottom Filters – Is There a Difference?

Yes, there is a difference between cone and flat bottom filters. The main one being that the shape of each filter affects where the water will seep through the grounds when brewing.

Cone filters have a conical shape. This means that the water must flow down into the center of the filter and then upwards and out again. This creates a slower and more even process of brewing.

Flat bottom filters, on the other hand, don’t have this same double walled system. Instead, water seeps through the grounds all at once, which can quickly over-extract your coffee and result in a bitter flavor.

So depending on your taste, you’ll have to decide whether you want a slow and evenly brewed cup of coffee (cone filter) or a faster extraction that could be more bitter in taste (flat bottom filter).

If you already have a coffee maker, you have to check which type of filter it uses. You can’t interchange between these, you have to use the correct one for your coffee maker design.

Size of Coffee Filter For Each Machine Size

The size of filter you need to use will depend on the capacity of your coffee maker.

Cone-Shaped Coffee Filter Sizes

Cone Filters are usually size by number: #1, #2, #4 and #6.

#1 – for one cup electric coffee makers

#2 – for 2-6 cup electric coffee makers

#4 – for 8 to 12 electric cup coffee makers

#6 – made mostly for large manual brewers up to 10 cups. (like Chemex for example).

Flat-Bottom Shaped Coffee Filter Sizes

Flat bottom filters are easier to buy because most of them are already labelled with the machine cup capacity. Most flat paper filters will fit an 8 to 12 cup coffee maker. If your machine is smaller and uses a flat-bottom filter, you’ll find a 1-4 cup size filter that you can use.

Substituting Filter Sizes for Different Pot Capacity

Can You Use a 4-cup Filter in an 8-Cup Machine?

Yes you can use a 4-cup filter in an 8-cup coffee machine, but only if you don’t plan on brewing the full 8-cup capacity. A 4-cup filter will hold enough grounds for just that, 4 cups. It will be shorter than the filter basket inside your 8-cup machine, but it should work. If you want to brew a full 8-cup pod, you can’t use the smaller 4-cup filter.

If you want to use a larger filter in a smaller machine, that is doable, too. You’ll simply have to slightly fold it to it becomes shorter, then use as usual.

Paper Coffee Filter Materials

bleached vs unbleached filter

Bleached vs. Unbleached Coffee Filters

Bleached coffee filters (white filters) have been processed with the use of chlorine and other chemicals in order to “bleach” them. Unbleached (brown filters), on the other hand, have not undergone any additional processing, so they are more natural.

If you’re concerned with the environment and don’t want to support companies that bleach their coffee filters with chemicals, it’s best to go with unbleached filters.


There’s the argument of which coffee filter can make better coffee, bleached or unbleached?

Unbleached paper filters, can sometimes, transfer some ‘papery’ taste into your coffee. This can happen with some bleached filters, too, but the chances are higher with unbleached ones. Which is why it’s always a good idea or rinse your paper filter before brewing coffee.

Other than that, there’s no real significant difference between the two. The choice is more of an environmental impact concern rather than ‘taste’.

Coffee Filter Alternatives – What To Use Instead?

We all have those days when we suddenly find out we don’t have coffee filters to use. You have some options to try from around your kitchen…

If you have a permanent filter that came with your machine, but you never used, this would be the perfect time to try it! Otherwise, try a few of these hacks.

1. Paper Towels – Line a couple of paper towels inside the filter basket, just like you would using a paper filter. Just make sure you’re using the thick kind, or double up if your paper towels are very thin. This hack is doable, but it’s not the best. It will transfer some unwanted taste to your coffee, and sometimes, the paper towel rips. Also, paper towels are not made of the ‘cleanest’ materials out there, they’re meant for cleaning and tossing and not for food or drink processing. They are definitely not safe to use daily as a filter substitute.

2. A Cloth Napkin – This is a better option than a paper towel because it’s thicker with less chance of ripping. But that much thickness could also lead to water not flowing quick enough, leading to overflowing or a really bitter cup of coffee. Try this ONLY if you really have to.

3. Tea Infuser – A tea infuser works just like a permanent filter. It has very small holes so it won’t allow the grounds to slip through, but be careful not to use too much coffee or else you’ll get a bitter cup of joe. You can use it directly into your cup, even. No need to use the coffee maker all together!

Can Baking Paper Be Used as a Coffee Filter?

No. Baking paper is not meant for that purpose and it’s not safe to use as a coffee filter. This type of paper does not drain liquids, so using it as an alternative to coffee filter won’t work, it simply won’t let the water through.

How To Use Coffee Filter Without Coffee Maker?

If you don’t have a coffee maker, but still would like to enjoy a cup of joe in the morning, you can use the pour-over method. This will require either a cone filter or flat bottom filter and a ceramic or metal holder where you’ll place the filter in, on top of your cup.

For this method, you’ll need to heat up your water separately and then pour it over the grounds. Once all the water passes through, you can enjoy a fresh cup of coffee!

Unfortunately, there’s no way to use a paper filter directly into a cup. But you can try placing a permanent filter over a cup or a pot and do a pour-over brewing method.

Frequently Asked Questions

Do I Need to Add a Paper Filter to a Permanent Filter?

No, you don’t need to. Permanent filters are made from metal mesh and they won’t let coffee grounds pass through. Some people do like to double-filter their coffee, in that case, you can add a paper filter to your permanent filter, but otherwise, it’s not necessary.

Where Is the Paper Filter Or Permanent Filter Placed in a Coffee Maker?

Whether you choose to use a paper or permanent filter, both sit inside the filter basket placed inside the lid of the coffee maker. The filter basket should not be removed, it is used to hold the filter correctly in place.

Are Paper Coffee Filters Compostable?

Yes, they are. These are an environmental friendly choice, whether you buy them bleached or non-bleached.

Are Paper Filters Flushable?

No, flushing your paper filter is a bad idea, especially if they still contain coffee grounds, which will clog your draining pipes. The filter on its own, while it’s biodegradable, it’s not as light as toilet paper, so it won’t go down the drain as easily.

Does a Permanent Coffee Filter Take Out the Coffee Oils as well as a Paper Filter?

They work well enough, but it always comes down to the brand and quality of the permanent filter, so it’s not always guaranteed. If you want the best filtration, a paper filter works best.

Does Using a Paper Coffee Filter Take Nutrients Out of Coffee?

Coffee isn’t naturally a nutrient drink. It has some perks of providing you with energy, but without filtration, it can be very unhealthy. So you actually want to use a paper filter to take out some of the unhealthy materials in it, like Cafestol for example, which leads to higher cholesterol levels.

Are Permanent Coffee Filters Safe To Use?

Yes, they are. While there’s always argument about the safety of metals like aluminum coming in constant with hot water, Permanent coffee filters are made from stainless steel mesh and, if of good quality, can provide you with a great cup of coffee for years to come. Just make sure to clean them regularly and properly so that it stays free of any build-up or dirt.