Five Senses Coffee Blog

Fine tuning the drip brewer

There is nothing more frustrating than having everything at your fingertips…nearly. This is kind of how I felt this morning when I embarked on my mission to explore what results I get using different types of filters. Essentially, when it comes to coffee drippers there are seven main variables that impact on result in the cup. There are other variables which I think have a small effect but pale into relative insignificance if you can’t get control over the big ones.

For the purpose of testing the effect of using different filters in the drippers, the variables that needed to be consistent were:

• The origin used. Today it was Guatemala La Perla.
• The particle size of the grind through the lab grinder.
• The amount of coffee used. (40 grams)
• The steep time.
• The volume of water. (330ml)
• The water temperature grrrrrr the water temperature. Get my frustration!! Uber Boiler – wherefore art thou!! I can’t say that using a kettle gives us the best chance of controlling this variable excellently but by using a thermometer probe we were able (with quite a bit of effort) to get relative temperature repeatability in each of the drippers.

We used 3 test filters:

• An unbleached flat bottomed Melitta paper filter
• An non-chlorine oxygen whitened flat bottomed Melitta filter
• A swissgold gold filter.

Melitta claim that there is no difference other than visual between their unbleached (natural brown filter) and their oxygen whitened filter. We thought that this was worth putting to the test.

We ran the tests both yesterday and this morning. In both instances the tests were done blind to prevent prejudice being a factor in our evaluation and eventually our preferences. The differences were absolutely evident and the results that we achieved replicated in both tests. In our taste evaluations we also concealed the coffee so that we couldn’t be influenced by what we could see.

The result:
Visually: The two paper filters produced coffee with no suspended particulates. The coffee resulting from the gold filter was very muddy in appearance.
Taste: The flavour and character was evident in all of the cups but varied in intensity and clarity. The white filter produced a coffee that we felt had the greatest amount of clarity while the gold filter produced a coffee with an almost overt intensity – almost masking some of the subtleties we enjoyed in the coffee made with paper filters.
Mouthfeel: The gold filter resulted in a brew with much heavier palate weight than the two brews made with the paper filter. This isn’t surprising. It has been known for some time that paper filter prevents the movements of lipids (which include unsaturated long-chain fatty acids) into the cup.
Usabilty: The paper wins every time. I think that the effort to wash the gold filter properly after every brew would probably be disincentive enough for me not to bother with making myself a brew. The paper filter is 100% biodegradable so with a quick flick of the wrist the filter, complete with spent coffee, is in the compost bin. The swissgold filter costs close to $50 while $2 – $3 buys you about 40 paper filters. It probably means that paper filters might cost you more money in the long run but I think that once you throw cleaning time, detergents and water into the equation you might re-evaluate the real cost of choosing one type of filter over the other.

Summery:
Quote of the day from Richo *pointing* “that one tastes like coffee” then pointing again at another “that one is more like a meal”. We enjoyed the result of each filtration method but I think that it is fair to say that our taste preference was for the coffee brewed with the oxygen treated paper. The gold filter would produce a cup that in isolation would be something that most people would quite enjoy. However, when tasted alongside a cup brewed through paper there was no doubting that our preference was for the oxygen processed paper filter.