ABSTRACT

In the heart of the Midwest sits the third largest city in the United States: Chicago. A sprawling, lake-side metropolis with a hustling and energetic undertone coursing through every person and building. Yet for all the might and history of Chicago, the coffee scene is in a deplorable state. Weekend outings for a good cup-of-joe are tainted and muddied by foul tasting coffee from shops that demand increasingly higher compensation. To remedy this dire state of affairs, Lilly and I recently bought our own espresso machine, grinder, and scale. Fear not, the dream of a good cup of coffee lives on.

INTRODUCTION

An espresso machine, grinder, and scale. Our goal is to create all forms of coffee beverages using these tools. We quickly discovered that there is a learning curve to transforming a bean into a beautiful, warm cup of coffee or a smooth delectable latte. Our working hypothesis is that given enough time and iterations we should produce coffee that is of equal or greater quality to the coffee locally distributed by shops in Chicago. Given the proper time, care, and attention to detail we hope to soon be basking in the wondrous smell and tastes of home brewed coffee every morning. 

MATERIALS & METHODS

Espresso machine (Breville)

Bean grinder (Baratza)

Scale 

Coffee beans (Colectivo Kenya Kirinyaga Karii)

Coffee mug

This is essentially all one really needs to get started. The instruction manuals for all devices are also useful. Youtube also provides an assortment of different expertise on all things coffee and espresso. 

RESULTS

Collected Data for Espresso Iterations

Iter.	Bean	g/shot	Yield (g)	Grind setting	Start pour (sec)	Start-end (sec)
1	Col. Kenya	9		15	14
2	Col. Kenya	9		10	14	46
3	Col. Kenya	9		20	12	28
4	Col. Kenya	9		22	11	14
5	Col. Kenya	9		18	12	21
6	Col. Kenya	9	47	16	12	27
7	Col. Kenya	9	41	14	13	33

Table 1. Collected data for seven iterations of coffee. All espresso was made for a double shot. The numbers in blue represent results in ideal ranges. 

Listed observations for each Coffee Iteration

1. Pours too fast. Liquidy. Too coarse. *Addendum note post experiment: Did not really know what I was talking about.
2. Slow pour. Liquidy. Very sour. Dark and bitter. Beans may be old. Over extracted.
3. Over extracted. Too fine. Coarser for next rep. Getting close. Consider bed depth. Ground coffee should not touch the machine.
4. Flying out. Under extracted. Too coarse. Forgot to check bed depth.
5. Numbers are not really making sense but I think I am making each cup with better technique now. Slightly underextracted.
6. I think around here is the best we are going to get. 
7. Hovering around the correct numbers. Still not the best taste. Decent at 14-16 grind setting.

List 1. Notes taken during espresso coffee production iterations. All notes were taken by hand immediately following an iteration.

DISCUSSION

While that perfect espresso still eludes our grasp, I can confidently say we are making progress. The subjective taste is significantly statistically better every cup. As I furthered my coffee education through Youtube, I definitely took note of some important espresso rules. Every different coffee bean must be dialed in with our equipment separately. There are no “one size fits all” solutions to espresso machine and grinder settings. Our total yield should weigh about twice (or a little more) than our initial bean mass. Tamping is not about force or pressure, but about consistency and remaining level. 

Perhaps most importantly was the consistent reminder that a good coffee bean is necessary for good coffee. The second we ground coffee it starts going stale extremely quickly. When we are buying a bag of coffee we should be looking for a “Roasted on” date instead of a “Sell by” date. A general rule of thumb is that freshly roasted coffee tastes far superior. Coffee only stays freshly roasted for 2-6 weeks. 

Allow me to speculate. Does all of Chicago just use old beans? Beans that have seen their prime roasted potential come and go? Only the coffeehouse owners of Chicago know the truth. But I would be wary of stepping foot into a coffee shop, expecting a good cup of coffee as the barista reaches for a bag of beans that have been on the shelf for an unknown amount of time. 

Luckily, we have fresh beans on the way. Roasted this week, with a brand we trust and know well. Stand by for further permutations, iterations, and inquiries into the espresso world.