We could not begin to talk about Wednesday, without referencing and thanking Connie Blumhart of Roast Magazine, for hosting us and the folks of Sustainable Harvest at her home Tuesday evening. We enjoyed excellent Chinese food, eating everything but our plates, (nearly filling our pockets with those potstickers), drank delicious wine and local craft beer, all the while conversing about everything from SCAA, to the Roaster’s Guild, tea production, and the potential appeal for specialty coffee publications in Japan. All our deepest thanks to Connie, and her wonderful family, for a delicious, welcoming evening.
Presentation - Day 2 Topics
The Second day of the presentation, like the first, was the designated to specific topics, those being coffee fermentation and the use of enzymes, and drying methods. This blog will be designated primarily to the first of those topics.
Fermentation within coffee, is the term used to describe the process of removing the mucilage of coffee, with water. This process is dependent on a number of conditions, water being one of them.
The significant lack-there-of within Beneficio El Manzano, as well as many parts of the world, started our minds thinking of ways in which we could simulate the fermentation process, or if possible expedite fermentation without the presence of excess water. The latter condition, takes away the option of heating tanks or agitating the water more frequently; but opened up our minds to the idea of introducing something external to the fermentation tanks.
We found an answer in enzymes.
First introduced to the idea by Tom Owen of Sweet Marias, we began testing the effects of adding enzymes to fermentation tanks on his trip to El Salvador, in the earlier months of 2011. He had taken with him, a powder enzyme that activated in water after 20 minutes, and through these first tests, became more interested in seeing the extent of the influence that enzymes could have. We thank Tom and look forward to drawing more conclusions with him in the future.
Enzymes are what exist naturally within the fermentation process to break down the sugars of mucilage. Their presence is essentially what enables fermentation to happen, however, as mentioned before, are only created over time, as water reacts with mucilage, specifically the sugars contained within the mucilage.
These enzymes, once present, quickly work to break down the mucilage, however, their presence is typically noted after several hours within the tanks, falling within a range of time anywhere from 16-36 hours. The amount of time can be less, but statistically should not be more.
Later correspondence with a few friends in the wine industry, concluded with a scheduled trip to El Salvador, with multiple vials of liquid enzymes, to use and experiment with, to see if they could in fact expedite the fermentation process of coffee, while limiting the amount of water consumed in processing, and without negatively influencing the cup quality.
Therefore, before experimenting, and introducing external enzymes, we wanted to be specific with what our intentions and objectives were in using and applying the enzymes to coffee. We began by asking some key questions, and identifying what the implications would be for the use of enzymes within coffee production, if they in fact worked as we hoped.
Questions asked before experimenting
“Cuatro M, Single Origin Coffees will begin experimenting and applying enzymes to their coffees, for the purpose of determining the extent of the effects that they could play in coffee processing.
- Can Enzymes help to break down the mucilage of a washed coffee?
- Will Enzymes help to also liquify the mucilage, and limit the amount of water needed to washed the mucilage from the bean, once broken down?
- If yes, they could thereby serve the purpose of achieving a more sustainable means washing and processing coffees, requiring less water; and thereby enabling coffees to be processed in areas where water sources are not prevalent.
- If yes, does the overall money saved, in the conservation of water, supersede that spent in order to acquire the enzymes?
- Can enzymes contribute to the development of a coffee, during the drying and resting process, and thereby improve the overall quality in the final cup.
- If yes, enzymes could thereby serve the purpose of improving the overall quality of a processed coffee.
- If yes, does the improvement in cup quality, hide the unique attributes of the coffee, or in any way, remove the terroir in a cup of coffee.
- Are enzymes natural, and do they pose any harm to the coffees themselves, or consumer.”
Acquiring enzymes from some friends within the wine industry, we began experimenting with and noting the effects of the enzymes when applied to coffee. First at our own lab, and secondly during and throughout the presentation, we demonstrated the quick effects of the enzyme, applying it to the beans of cherries we de-pulped by hand in the conference room.
The audience themselves were able to de-pulp the cherries into clear glasses, at which point we added water and enzyme, and began to watch the enzymes work within the water, to liquify the mucilage in as little as one hour; pictured right.
Throughout the harvest, at El Manzano, we were able to use two different types of enzymes to set up a controlled experiment. Here we used the same batch of coffee, and fermented them in four different tanks, enabling us to measure the influence and effects of different enzymes to the same coffee.
The first two containing each individual enzyme; the third, a mixture of both, and the fourth, no enzyme, acting as the control within the experiment.
Allowing the coffees to sit over night, we observed a significant influence on the part of the coffees fermented in enzymes, completely breaking down and liquifying the mucilage in as little as one hour, while the control coffee still contained much of the mucilage after as many as 16 hours.
We then, only drained the coffee of the fluid, and moved them to the patio to dry. We repeated this experiment four times, drying the first two on the patio, while using the African Beds for the final two.
The addition of enzymes did in fact contribute to and expedite the fermentation process.
The addition of enzymes did enable us to consume a significantly smaller quantity of water, as a final rinse was not necessary to wash the mucilage from the beans, as the mucilage had been liquified by the presence of the added enzyme.
Development of acids and sugars in fermentation
One of our initial questions was geared around whether or not the additional, external enzymes would reduce the level of acidity within the coffees, usually present within natural fermentation.
Throughout the fermentation, we measured both the pH and sugar content of the mucilage water.
What this graph shows is both the levels of acidity and sugar, rising within both the Enzyme and Naturally fermented coffees. The longer the mucilage rests in the fermentation tanks, the higher percentage and level of sugar and acidity is present.
We are still searching for ways of measuring and analyzing the full activity and extent of acids present in both the natural fermented coffees, and the coffees fermented with external enzymes. From our measurements, it appears that the levels of acid and sugar in both tanks is very similar. Since there are different types of acids developed within the fermentation process, the next step will be to analyze the different kinds produced within both tanks.
These acids are both practical and desirable, because they contribute to final cup quality, as well as fight against bacteria and fungus throughout the coffees time on the patios and in the warehouse.
Another of our objectives was in noting whether or not the enzymes influenced the final cup quality of the coffees. Although we had cupped the enzyme coffees in our own lab at El Manzano, we had yet to hear from professionals within the industry, their opinions, not on the use of enzymes, but solely on cup quality. Therefore, we made the cupping the experimental coffees the first thing on the agenda for Wednesday morning, performed the cupping blind, giving no indication of whether the coffees were the from the same plantation, processed with different methods, etc.
The results would prove a unanimous preference for the enzyme fermented coffees, over that of natural fermentation; illustrating that coffee fermented in less time with external enzymes, maintained and even gained cup quality over the drying, resting, roasting, and cupping process.
Cupping notes from an audience member: (Same coffee, Enzyme added).
- Control Batch 248: 84 Balanced, heavy body, mild acidity, chocolate sweetness. Only negative, a bit murky in the clarity of the flavor.
- Enzyme Batch 248: 85.25 Light body, crisp flavor, floral and citrus notes, bright citrus acidity, short crisp finish.
- Control Batch 253: 83.75 Very similar to Enzyme 1, but not as much sweetness in the aftertaste.
- Enzyme Batch 253: 85 Light body, more juicy sweetness in flavor, a green apple acidity, lingering sweet finish.
With the results of the cupping from our experimentation, we conclude with these observations, and the implications that they could have for any operation worldwide, that does not have an abundant supply of water.
- The coffee fermented with external enzymes reduced the amount of time required for the fermentation process.
- The coffee fermented with external enzymes reduced the quantity of water consumed in the process.
- The coffee fermented with external enzyme received higher cupping scores from multiple members of the coffee community.