Bleached vs. unbleached coffee filters

"And please, a double filter for the sixty," I say to the barista, remembering that I won't have anything to make coffee in tomorrow.

"And do you want bleached or unbleached?"

There it is again - my decision paralysis! What kind and why I should want and how I finally decided will be discussed in the following lines.


How did the coffee filter come about?

The inventor of the coffee filter is German Melitta Bentz. Yes Melitta! She invented paper filters in 1908 by folding a leaf of a drinker (anyone else remember the drinker?) and letting the coffee being brewed drip over it. Melitta, which Mrs Bentz founded in the same year, now makes drip coffee machines, drippers and other coffee accessories including paper filters.

Melitta Bentz

Bleached vs. natural

There are usually two types of paper coffee filters available on the market: bleached and unbleached. Bleached filters are, as the name suggests, white. The paper used to make the filter undergoes a chemical process that bleaches the natural paper.

Unbleached filters, on the other hand, are brown and do not undergo any chemical processing. Although they serve the same purpose, there are a few key differences between them.


Fabric, metal or paper filter? Read the article for more coffee filtering options!


How are filters bleached?

The paper used to make white filters is always chemically bleached. This is achieved using either chlorine or oxygen. Chlorine is harmful both to the people who work with it and to nature if there is a major leakage. Oxygen is therefore slightly more gentle for bleaching paper.

Unbleached filters, which are made from natural paper, are therefore more environmentally friendly. They are also usually slightly cheaper.

Different types of coffee filters | uncoolcoffee.com

But there is another variable. Using chlorine is much cheaper than using oxygen, so the cheaper white filters just go through the chlorine process. Chlorine thus helps manufacturers keep the final cost low.

But not to worry - firstly, the amount of chlorine in the filters themselves is virtually zero, and secondly, companies must state on the filter packaging which method of bleaching they use. The process involves a reaction between sulfur dioxide and sodium chloride, which binds with the pulp and fibers in the paper and removes the lignin that causes natural paper to have the color it does.

Why are filters bleached?

Well, that's the question. The original reason is probably very superficial. It's that we simply find white filters prettier and more hygienic than plain brown filters. And somehow we've just got used to nice white things on the shelves, and the manufacturers know it.

The main advantage of bleached filters

Bleached filter for Chemex

In defence of bleached filters, it's worth adding that they don't release as much of the paper taste during preparation as natural ones, because it's gone with the colour during the aforementioned chemical reaction. There is therefore no need to rinse them so thoroughly. However, I recommend rinsing with hot water for both types. After all, there are few things worse than looking forward to a cup of a great selection, going through the whole ritual, and discovering at the end of it that you are drinking paper.

Is a bleached or unbleached coffee filter better?

Many coffee geeks theorize that unbleached filters are better than bleached filters because they don't use as many chemicals in their production. And they're basically right.

If you pit bleached and unbleached coffee filters against each other, for all we know today, the unbleached, natural ones are actually more likely to win. They're more environmentally friendly and they tend to be cheaper.

Still! Undoubtedly, bleached filters are better in that they do not affect the taste of the prepared coffee when rinsed less thoroughly. So of course, the choice ultimately depends on everyone's preferences.


Personally, I've had my barista explain it to me and from now on I always consider the environmental impact of my choice of coffee filters. And I'll be rinsing them thoroughly too. How about you?


Frequently asked questions

Are bleached filters safe when you write about chlorine etc.?

They are and there is nothing to worry about. The fundamental problem with the use of chlorine is where the bleached paper is made.

Are there other options than paper filters?

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