Report on the SCAA Chemistry Questionnaire

By Emma Sage

The idea behind this questionnaire about chemistry and coffee was to assess the level of understanding and interest within the SCAA community. In the future, we have the opportunity to incorporate more or less chemistry into our class and certification materials, depending on what we hear from our members. This questionnaire allowed us to understand the average introductory level of content we should incorporate as well as your opinions as to if or where it would be helpful for your business.

In total, 434 people at least looked at this questionnaire. Nine of these never answered any questions, and about half of them didn’t answer any questions past the demographic info. For those questions actually dealing with our opinion on chemistry and how it may or may not help our understand coffee in the future, an average of 158 people answered, about 36%. Of these, about 72% were baristas and 30% were roasters, 30% of which were also trainers and cuppers.

Part I: Interest in chemistry and applicability to business:

We asked you to express your interest in taking classes which included a variety of chemistry-related topics. The most popular topics, from the highest to lowest interest, are listed in the below table:

When we asked how you could improve your work by learning more about coffee chemistry, 161 people answered. The highest percentage of people (36%) said that they thought generally learning about chemistry would help them increase the quality of their product. Twenty-five percent of people didn’t know a specific application of chemistry, but expressed that they thought that learning about it would be a good idea. Some (13%) mentioned how learning about chemistry would help them communicate within the coffee industry. Others (11%) felt that learning about chemistry would be help them be able to associate chemical compounds with flavor and this would improve their work. About 30% of people thought that it would be helpful to be able to name chemical compounds responsible for flavors in the cup (of 191 answers). A good portion (19%) mentioned that this would impress their customers. Again, some (28%) said it would be better for within-industry communication. Ten percent of answered stated that this would not be helpful. Five percent included that it would not be beneficial, but it would still be cool.

When we asked what type of chemistry would help improve your business? (of 197 answers):

Brewing chemistry = mentioned by 23%
Roasting chemistry = mentioned by 19%
Any/all = mentioned by 16%
Basic, entry level chemistry only = mentioned by 16%
Espresso chemistry = mentioned by 10%
Sensory/flavor chemistry = mentioned by 7%
Water chemistry = mentioned by 6%

Part II: Who remembered high school?
Believe it or not, we were not judging you with these questions! We simply wanted to assess the level that the majority of our members understand chemistry. We will use this to better inform the level of information and language used in current and future SCAA classes.

Most of those who answered the questions about basic chemistry (around 150) remembered:

That a pH below 7 was acidic (72% answered correctly)
Covalent bonds are considered strong (82% correct)
How to draw molecules (53% knew that there were 6 carbons in the benzene ring)
The water molecule (89% correct)
Generally, what a volatile molecule was (62% correct)
That water goes from a liquid to gas phase when boiled (83% correct)
An isomer is a different structural configuration of the same molecule (25% correct)
A carbohydrate is made up primarily of carbon, hydrogen, and oxygen atoms (21% correct).
Many more (34%) knew that carbohydrates were generally known as sugars.
Finally, perhaps because we are biased, 67% recognized the caffeine molecule.

Part III: What is known about acidity in coffee?

When we asked why acidity was important in coffee (which is a subjective question with a variety of “correct” answers), 135 people answered. Many (41%) mentioned that it was generally associated with good flavor. Twenty-one percent said it was important for the flavor balance of the cup. Twenty-six percent said it was responsible for the brightness or liveliness of the cup. Other mentioned everything from mouth-feel to sweetness, freshness, cleanliness, quality, fruitiness, and bitterness.

When asked about the flavors characteristic of malic acid, 37% of 130 answers mentioned the apple flavor, which was the simplest correct answer. Thirteen percent mentioned sourness, 7% mentioned wine or grapes. Other answers included pear, melon, fruit, sweetness, milk, bitterness, malt, berries, vinegar, barley, toast, and chalk, perhaps confusing it with other acids. Most people (60% of 129) were also able to identify that acetic acid was vinegar. Some (9%) confused this with citric acid. One person confused it with malic acid.

Of 127 answers, 26% admitted they did not know how origin or terroir affected acids in coffee. This is understandable, as we know very little about this scientifically. What we do know is mostly from industry-based knowledge and depending on your training you would know different amounts about this. However, we are still waiting for science to support much of this. Some people (23%) thought that the soil had a large impact on acidity in coffee, which it may, and some think that the level of phosphates in soil relates to the amount of phosphoric acid in coffee, but we really don’t know specifics on this. Others (11%) mentioned altitude. Specifically, 9% mentioned that higher altitude was associated with higher acidity, which albeit may be known within the specialty community industry has yet to accumulate much scientific evidence to support it. Others mentioned climate and weather, fruit ripeness, plant metabolism, and speed of plant growth affected the acidity of coffee. All of these are believed to influence the acidity in coffee, but again we have limited scientific evidence to support specifics on this.

What happens to acidity during roasting? This was a vague question due to the truly huge diversity of possible answers. Typically, at the SCAA we focus on the few acids that are most prevalent in coffee. Depending on the acid, these go through different chemical reactions during the roasting process. This question was a difficult one, but it highlighted some confusion within the community. Of the 144 people who answered, 37% thought that acids were simply broken down and decreased during roasting. Ten percent thought that they simply increased. Sixteen percent knew that depending on the acid, some increase and some decrease, which is correct. Some (13%) even knew that some acids increase until a certain temperature of roasting, at which point they cross a threshold where they break down and decrease.

When we asked what happened to acidity in coffee when it was left on the heat for a long time, we received a variety of responses. Most (42% of 131 answers) thought that generally, over time acidity was broken down and decreased. Actually, chemical reactions continue to occur while the coffee sits on the heat, and acidity continues to form. Twenty-seven percent of you answered with this, understanding that coffee gets more acidic with time after brewing. Interestingly, 17 people thought that the acids turned bitter over time, indicating that they thought bitterness was a product of acidity, versus being a taste associated with certain acids. Very few people answered that the acidity would not change in this scenario.

Overall, we learned a lot from you via this questionnaire and we really appreciate you taking the time to complete it. In the future, we hope to utilize science, including chemistry, into our SCAA classes and certifications to give you the power to create better tasting and more profitable coffee!