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!