As one who is frequently obsessed with finding the optimal solution or the perfect product, I intend to definitively find out which variety of coffee beans is my favorite.

If you are reading this just for fun, I suggest you to scroll all the way down to the conclusion part.

Beans Sourced

Thanks to this and this article from The Washington Post, I drove to four highly revered roasters in DC to purchase the following beans:

M. E. Swing's

Brazil
Sumatra
Kenya
MESco Blend (Guatemala, Brazil, Ethiopia, Light Medium Roast)
G Street Blend (Costa Rica, Guatemala, Medium Dark Roast)
Diplomat Blend (Guatemala, Costa Rica, Sumatra, Dark Roast)

“Located on the corner of 17th & G Streets, Swing’s on G is about one Doug Flutie 'Hail Mary' from the White House.”

Swing's has been around for almost 100 years. It’s close to where I work, and it was my default choice of roaster for a long time.

Qualia Coffee

Mogiana, Brazil
Ambiental Fortaleza, Brazil
Silimakuta, Sumatra
Monte Verde, El Salvador
Bebeka Estate, Ethiopia

Qualia is dead serious about freshness. They put fresh off the roast beans on a pretty small shelf. Anything on that shelf that's not sold within three days is automatically off. They roast in very small batches, and their source of bean changes seasonally.

Compass Coffee

Serra Negra, Brazil
Cardinal Blend (Americas, Medium Roast)
Waypoint Blend (Americas, Dark Roast)
Embassy Blend (East Asia, Medium Roast)
Azimuth Blend (East Asia, Dark Roast)

Compass Coffee was found by two former US Marines. Rather than confuse the heck out of novices by throwing all kinds of lexicons at them, Compass has a crystal clear table for their blends’ origin and roast.

Vigilante Coffee

Maui Mokka, Hawaii
Sumatra

Vigilante specializes in single origins. Their roastery is a funky place that's fairly close to College Park. Be sure to check it out if you live nearby.

Aroma Coffee Roast

Kenya
Monsooned Malabar
New Guinea
Brazil

Albeit not a DC local roaster, Aroma is the roaster of choice by Marco Arment, who is way more obsessed with perfection than I am. (Plus that he is probably my favorite person on the Internet).

Brewing Methodology

All beans were roasted within two weeks before the cupping tests and ground within 5 minutes before brewing.

Brewing Method: AeroPress with the Inverted Method
Grinder: Baratza Virtuoso with a fineness setting of 9
Bean to Water Ratio: 15:190
Water Temperature: 200F
Immersion Time: 30 seconds for blooming, 60 seconds afterwards

Subjectivity

Before I started the tests, I wrote:

I will conduct double-blind randomized controlled trials for the cupping tests, but don’t expect it to be objective. Again, everyone’s taste is different. The actual review is coming soon. Well, soon-ish.

The reality was that it took me a month and a half. Not even remotely soon-ish. The cupping tests were much more challenging than I expected. Making a cup of good coffee is not difficult. Nevertheless, it is pretty darn difficult to make four cups with different beans, meanwhile trying to keep it a double-blind controlled experiment. I found myself frequently losing track of the types of beans I used. Did I just grind the Brazil from Qualia or Compass? Is Cup B the Cardinal Blend or the Embassy Blend? Additionally, because time was severely constrained, it was impossible to not screw up every once in a while. Maybe I added 15 grams more water than I should. Or maybe I let the beans immersed 30 seconds more than I should. After all of that effort, now try to drink them all while they are warm and carefully write down tasting notes...

Eventually, I gave up on maintaining this review as a controlled trial. Drinking coffee is supposed to be delightful, whereas conducting rigorous empirical research is not.

Conclusion

Degree of Roast

Before the tests, I also wrote...

Traditional coffee purists argue that single-origin, medium to light roast is the correct selection of beans. Nonetheless, I dislike the acidity often found in lighter roast...

It turns out that they were right about light roast. The problem with dark roast is that it has a mask effect, similar to that of milk and sugar, on the taste character of the beans' origin. In another word, all dark roast taste pretty much the same. Perhaps this is a blessing for casual coffee drinkers. The pre-ground coffee from Costco can taste just as good as the Diplomat Blend from M.E. Swing's, so long as they are dark roast.

On the other hand, light roast is much trickier. I'm still no fan of strong acidity, but I find that some beans possess a somewhat complex acidity that is in fact pleasant. Furthermore, light roast enables you to experience the fascinating taste of the beans' origin.

Origin of Beans

Generally speaking, coffee beans are divided into three geographic groups:

1. Africa. Fruity taste.
2. South East Asia. Earthy, smoky, and herbal taste.
3. Central and South Americas. Nutty and chocolate-ish taste.

And yes, you can actually tell the difference.

And the winner is...

Brazil from Qualia Coffee. It's truly difficulty to describe it in words. I did, however, tried Brazilian beans from all five roasters, and the ones from Qualia is clearly superior. It has a delicious nutty taste, sophisticated acidity, and extra-strong aroma.

I also quite like Qualia's Sumatra. Its earthy taste resembles that of your everyday dark roast coffee, only more complicate and enjoyable.

Lastly, Compass Coffee's Cardinal Blend is likewise great. It's a blend of beans from Central America. A lot of coffee advertises that it has a hint of chocolate in it, but the Cardinal Blend actually does.

Again, these are only subjective personal preference. It is entirely possible that you order the exact varieties of beans that I mentioned above (or from any other coffee enthusiast), only to find that they are completely unpalatable. Yet, that's the tricky and interesting part about good coffee. It's probably not going to be easy to find your own favorite, but once you do, your life will be filled with sheer awesomeness.

(You will also save a considerable amount of money by forgetting about Starbucks.)

Update Notes (September 2016)

I had the fortunate to try out many more beans from Qualia, especially their Central and South America selections. Nevertheless, their Brazilian coffee remains my personal favorite.