Chemex FIlter

Chemex filters :: bleached vs. unbleached

Published by Victoria Gormley
May 27, 2015 2:44 pm

We have quite a few people come through asking about the differences between the two types of paper filters: bleached, and unbleached. To be honest, because we don’t carry unbleached filters, I had never tried them! So we decided to do a side-by-side test, and here is what we found.

For this experiment we made sure to use the same medium sized grind for both brews. We weighed out and used the same amount of coffee (50g) and the same amount of water (780g) for both, and the same 200º filtered water for both.

We made sure to pre-wet the filter quite a bit before adding our coffee (this is always a good idea for pour overs). Between wetting the filter, and the actual brew cycle, I noticed a paper towel smell from the unbleached filter that I haven’t ever smelled with the bleached. Just an observation! Next, we began to brew. While the coffee was blooming (the first 100g of water for the first minute) I sat back and compared the rate at which both were brewing. There wasn’t much of a difference between the two, but overall the bleached was slightly quicker. This was the same for the overall brew cycle.

After the brew cycle was finished, I cupped both and let them cool for about a minute. I found the bleached filter had all of the qualities of the traditional Chemex we’re all used to: a clean, smooth cup that has very balanced flavors. The unbleached filter wasn’t terrible, but I did notice it lacked the smooth, balanced flavors and it also had a paper flavor to it.  While the differences weren’t extreme, I personally enjoyed the bleached better. Once I tasted both, I poured three cups of each and had Mark, Paul and Hayley try them (none of them knew which cup was which). Both Mark and Paul quickly decided they preferred the cup that had been from the bleached filter, as they noticed a paper-like flavor from the cup that had the unbleached filter. Hayley was a little more neutral, but noted the cup that had used the bleached filter was much more smooth and balanced.

If you notice you don’t like the flavor of unbleached either, but maybe don’t want to work with bleached filters, give the Able Kone a try. The larger pores in the stainless steel, reusable Kone make for a slightly heavier bodied cup than paper filters do, but certainly delicious.

Have you done this experiment before? Leave a comment below and let us know what you think!

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  • Written by: Andrew

    I’ve always heard my friends talking about rinsing their paper filters, which is why I went with Yama. How do you feel their cloth filters compare to the unbleached paper filters?

  • Written by: Hayley McNabb

    Hi Andrew, I haven’t tried the cloth filters myself but I have friends that swear by them!

  • Written by: Ben

    Cloth filters are wonderful, they produce a very smooth yet nuanced flavor, full, but refined. A cloth filter will still allow the oils from the coffee into the brew, whereas a paper filter prevents the oils from entering the brew, resulting in a more “stale” taste, removing much of the fringe flavors. If you prefer that straight, hard, edged taste of most diner and drip coffee, then go ahead and stay with the paper, but if you want a full taste of the bean closer to the aroma, I recommend cloth. Using a metal or ceramic filter will also result in more flavor, but because of the fines they allow through, it results in a very robust taste, sometimes with a slightly rough or fine-grained texture, that can often mask more subtle flavors.

    The biggest disadvantage to cloth is that you have to keep it wet, you cannot let it dry, or the coffee absorbed in the cloth fibers chemically changes and inserts a terrible taste into any coffee you brew thereafter. In that, it is similar to tofu, when it is not in use, change the water every couple days and keep it submerged (or use new cloth each time, but that is a waste).

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