A Deep Dive into Coffee - UC Davis Pre-College Program

For two weeks in July I was given the incredible opportunity to participate in a pre-college program at UC Davis. During this program, I got to live on campus and take a class by Jason White on the Chemical Engineering of Coffee. As a hopeful food science major, I was super excited to learn all of the science behind a perfect cup of coffee!

Our classes started more introductory level, with learning the different ways you can brew coffee, with a simple Mr.Coffee machine, or with something more like a French Press. As we experimented with different brew techniques, we tasted each cup of coffee to figure out what was most palatable. As a class, we also began to look at the engineering side of things and figured out how the Mr.Coffee machine worked, tracked the inputs and outputs of a Mr.Coffee machine, and looked at how much energy was being used. After thoroughly exploring the Mr. Coffee machine, we examined other methods for brewing coffee and the energy required for those techniques as well.

After spending a lot of time focusing on brewing coffee, we looked at the roasting process. We experimented with different roasting techniques and settings. We were able to change the power, time, and fan level of our roasting machines. After hearing from experts who roast coffee every day, we determined that the best roast was created by starting a high fan setting and low power, and then slowly changing the 2 during the roasting process and ending with a low fan setting and high power, to create an even, delicious roast. After roasting a ton of coffee, it became time to strategize!

During the 2nd half of the 2nd week of the program, we were given a main goal: Which lab group could create the best cup of coffee with the least amount of energy? All coffee was put through a blind rating system, and scored(from -10 to 55), and energy was calculated by group to create a final score. Me and my lab partner ended up winning this challenge by creating 938 g of coffee with only 0.17 kWh total.

Our approach was to only heat the water to 80 degrees C, instead of a typical higher temperature, to save energy, and then use a grind size of 34 in the French press, and let the brew sit for 5 minutes to create the perfect coffee! In terms of roasting, we used a mix of 2 different roasts that we made. The first one was Honduras Green beans, roasting for 5 minutes, starting with a fan of 9 and a power of 5, and slowly changing then until the fan was 3 and the power was 9 at the end of the roasting process. This created a medium-dark roast. We combined this roast with a similar Honduras roast, where we roasted green beans for 4 mins, and started and ended with the same roasting settings. We also let the beans rest for 24 hours before brewing them. I am so happy with how our coffee turned out and how well we were able to conserve energy!

I loved this entire program and hope I can go to UC Davis again one day to continue to explore their impressive coffee research!

Textbook Used: The Design of Coffee An Engineering Approach, Third Edition (By: William Ristenpart & Tonya Kuhl)

Final Video that Explains our process:

I decided to link all of my lab reports below:

Lab 2: https://docs.google.com/presentation/d/15WAAY2DOyi2r0w88He916j_Rvd2DanIQ5pnepUSSNNw/edit?usp=sharing

Lab 3: https://docs.google.com/presentation/d/1-TXd5KToTGrV_6zJ20QhvRZIRF5MBwHjz07UFux5vJg/edit?usp=sharing

Lab 4:

https://docs.google.com/presentation/d/1qc1QNZmiBXoKltgULBQY_z-KbaYqxUliiMyHWaxfIyw/edit?usp=sharing

Lab 5:

https://docs.google.com/presentation/d/1XkmM_8hWq7jLsDs2PDTnBt-ReTUJBlNWMwWUmuelWyA/edit?usp=sharing

Lab 6:

https://docs.google.com/presentation/d/1S_VZaprI4JZvh-J08Apd2VmIO0eO7pG8sfEWQd_pzs4/edit?usp=sharing

(skipped lab 7)

Lab 8+9:

https://docs.google.com/presentation/d/12FWSYU2dgntIFqB4SxrI0DV22Hj31SQ0ptVhO_a6tg0/edit?usp=sharing

Final Slideshow:

https://docs.google.com/presentation/d/1-homwX0zvz9uZgP3uIJ74NUD5zDAqpVLiCRKCMfuydU/edit?usp=sharing