During my senior year of college at UC Davis, I took an introduction to chemical engineering class that taught its basic concepts through the medium of coffee. I was intrigued by how the class took something so many college students were familiar with, coffee, and utilized it to teach a concept as complex as chemical engineering. However, over the course of the class, we came to learn that the basic concepts of chemical engineering were not that hard to grasp at all—at least, not when you have coffee to help you learn them!
As a high school teacher, I often look for models and investigations that can make chemistry more relatable to students. As I reviewed the NGSS standards and HS PS 1-5 (“Apply scientific principles and evidence to provide an explanation about the effects of changing the temperature or concentration of the reacting particles on the rate at which a reaction occurs”), the coffee lab from college came to mind. Why not combine chemistry and coffee again, but this time as a teacher instead of a student?
To secure the funds needed to purchase the equipment needed for the lab, I applied for a grant from our local water district. The grant is dependent on creating a lesson that ties in to water, and coffee, as my students learned in class, is roughly 98.5% water! The next step was to invite local coffee shops to participate with us and donate their time and coffee beans to our lab. I reached out to a friend of mine at Bodhi Leaf Coffee and he was able to provide coffee beans and his expertise by coming in to teach my students the basics of brewing coffee. I also reached out to Mantra Coffee Shop, who has a page on their website dedicated to giving back to the community they serve. They also agreed to supply our students with coffee and send their coffee trainer to come and speak to our students on the fundamentals of coffee roasting. It was quite a nice to surprise to find two businesses who were willing to donate their time and resources to our classroom. Through their participation, students saw members from their community investing in them. As a result, buy-in for this lab was much higher than the typical activities I facilitate in the classroom.
Over a two-week period, students embarked on a journey to design a cup of coffee in the most energy efficient manner they could. During the first week, students were exposed to the different variables that go in to a cup of coffee. Students learned about how the temperature of water, the rate of extraction, grind size and roast profile all affect the overall taste of coffee. Students utilized different brewing methods and received feedback on their work from the coffee professionals who came for a classroom visit. Although students were initially taken aback by the concept of drinking black coffee, over time students became more receptive to the idea and even began comparing tasting notes with the help of a coffee flavor wheel I put up in class.
During the second week, students were tasked with taking what they had learned the previous week to design their own coffee using recipes of their own formulation. With the only constraint being the amount of water used, groups chose their own water to coffee ratio, grind size and type of bean. Students recorded their data using data tables, and over a three-day period they completed multiple trials to get their ideal coffee down. On the fourth day, students presented their final designs to a panel of judges, including the professionals who had stopped by the previous week in class. The judges’ overall ratings on coffee flavor and strength, and the overall amount of energy (in kilojoules) used in grinding the beans and boiling the water, were taken into consideration to determine an overall winner.
During this lab I incorporated a few different strategies that worked really well:
1. Utilize a Pre- and Post-Lab Survey: With the suggestion from a mentor teacher, I created a pre- and post-lab survey in which students answered a battery of questions about the coffee lab. Over the course of the lab’s two-week period, I saw a statistically significant change in responses to Questions 4 and 5 on the survey:
|Pre Lab Question 4||Average Score||Post Lab Question 4||Average Score|
|I am looking forward to working with professionals who work with coffee for a living||3.7/5||I enjoyed working with professionals who work with coffee for a living||4.0/5|
|Pre Lab Question 5||Average Score||Post Lab Question 5||Average Score|
|Turning classroom assignments in to competitions makes classroom activities more interesting||3.8/5||Turning classroom assignments in to competitions makes classroom activities more interesting||4.1/5|
This data not only informed my teaching and how I want to design future labs, I also shared this with my students as well. As we broke down the numbers, students also identified certain strategies that would help them better engage in their learning.
2. Provide a meaningful reward and engage the community: As a prize for designing the best tasting cup of coffee in the most energy efficient manner, the winning team will have their recipe replicated by Mantra Coffee Company and featured on their pour over menu for a three week run. I’ve experimented before with using contests and connections with businesses to broaden an interest in science, and this strategy continues to give my students fun and meaningful experiences. When the students found out that their design could potentially be on a menu of an actual coffee shop, their commitment and buy-in to the lab increased significantly (as we saw in the surveys).
In addition, the winning team, in a collaboration with our local Industry Business Council, held a tasting at our local “Taste of the Town” event. Students were recognized for their contribution to the event, served over 500 members in the community, and got to taste different food samples from local businesses.
As a final treat, I took my students on a half day field trip to the coffee shops we partnered with, where students got an in-depth tour of the coffee roasting and grading process. None of this was expected in any way, but through contacting local businesses and companies, you will be quite surprised at how many are interested in giving back to the community but just need a tangible and feasible way to do so.
3. Incorporate technology: As their final assessment, each group had to design a video in which they share their coffee design on YouTube. Students were challenged with creating a video that demonstrated how to make their ideal cup of coffee and shared their tasting notes and opinions on their coffee. Giving students the ability to share their work in a different media besides pencil and paper really showcased the different talents some of my students bring into the classroom. Examples of some projects are included here and here.
Just as students had learned the basics of brewing coffee from professionals, creating videos now allowed students the opportunity to communicate their learnings to others who might be unfamiliar with the science behind coffee. As a part of the project, I gave students the option to leave their video unlisted on YouTube so only students from the class with the link could see the videos. While some took that path, many posted their videos on their individual school accounts and made them visible to the public as they were eager to share their brew and what they learned.
Although this lab took some time to plan, it was the most fun lab I taught this entire school year. Watching students invested in their work and watching others invest in them was a rich and fulfilling experience. Having a two-week supply of coffee did not hurt either!