The Big Question: Bleached or Unbleached?
Any barista will tell you – well, maybe not all but most – that you should never use unbleached coffee filters. Why? What’s wrong with using the more eco-friendly paper filter to make coffee?
For coffee lovers who use the pour-over method with the chemex or coffee drippers, a paper filter of some sort is used to prevent the coffee grinds from finding its way into the coffee pot.
There are usually two types of paper filters to choose from: Bleached or Unbleached
Unbleached paper filters are similar to the paper grocery bags you would find at the supermarket. They tend to have a rather strong, grassy and card-boardy smell to it. It’s the unrefined/raw stage of paper.
Bleached paper filters, on the other hand, are the refined and processed stage of paper. They are usually bleached with chlorine or oxygen; the ones I find at the local cafes and roasters are the oxygen-bleached since they are much safer. They don’t really have a distinct smell.
I first started brewing coffee at home using the unbleached paper filter. After visiting various cafes and gaining some knowledge about brewing coffee, I switched to bleached paper filters. Since I never had the chance to really compare the two, I decided to do a little experiment.
A little Experiment: Passing Hot Water Through The Paper Filters
My Little Experiment in Order:
- Use Water at around 96 degrees celsius or 205 degrees fahrenheit
- Keep the paper filters dry before pouring the hot water. In other words, don’t pre-wet them
- After passing the water, compare the smell and clarity of the collected water
- Have a whiff of the used filters and compare the smell
The dripper didn’t really matter to me. So I decided to go with a dripper close to the shape of the Kalita dripper.
As far as I can say, there wasn’t much difference in the colour of the water.
I had a feeling that the unbleached filter would have a slightly faint yellow-brown colour but that wasn’t the case.
What I did find obvious was the smell of the water. The unbleached one had a very cardboard-like smell to it. On the other hand, the water from the bleached one had no smell in particular.
The same went for the used paper filters. The unbleached paper filter had a very strong and distinct smell while the bleached did not.
Another thing I noticed was the speed and smoothness of the water flow from the dripper to the collecting pot.
The water dripped steadily and constantly for the bleached paper filter while the water flow was unstable for the unbleached paper filter. I’m not exactly sure why, but I think the uneven spread of micro fibres in the unbleached filters created this phenomenon.
Conclusion and the Things I could have done to improve the experiment
I have to be honest, I will never go back to using the unbleached paper filter. I don’t know how much I’ll be destroying the planet by using bleached paper filter, but it’s just that I really can’t stand my great coffee roasted by a great roaster to mix with water containing impurities from the unbleached paper filter. The water from the unbleached paper changes the taste and I really can’t and won’t be able to taste the beauty of the coffee at hand.
Now, I know people who use the unbleached paper filter. They say that you should first pre-wet the filter and get rid of the collected water. That way, all of the ‘bad stuff’ from the filter is gone. But seriously, I don’t know if ALL of it may go away. Also, the selling point of unbleached paper filter is that it’s ‘eco-friendly’. But I’m not sure how big of a margin that is compared to bleached paper filter. And the last thing I do hear is that unbleached filters, made with quality, won’t be as bad as the cheaper ones. I did use unbleached coffee filters from a well-known coffee/import retails brand in Japan so I’m not sure if that’s the cheaper stuff or if I’m missing something.
What I want to change if I get the chance to repeat the experiment.
- Pre-wet the paper filters and then repeat the experiment.
- Repeat the experiment using water at around 80 degrees celsius or 176 degrees fahrenheit
- Use filters made from various different companies
At this stage, I’m still naive with my conclusion although I do stand by what I say.
I definitely need some more info and data to really solidify my statements. I have a feeling that once I do the things I’ve listed above, it’ll become clear as to which type of filter is best for extracting that beautiful cup of coffee.
I wonder what you guys think about this. Have you ever tried comparing the two? What did you think?
Do you prefer one over the other? If so, why? It’d be great to hear your thoughts.