Updated: Dec 17, 2021
A microclimate at play
Coffee is one of the most popular beverages in the world. It's an essential part of our morning routine, and it's also a delicious beverage to enjoy after dinner with friends. But as you may be learning, there are many other aspects to coffee than just drinking it! In this post, we're back with the third installment of our series, 'Farm to Cup in Kona, Hawaii,' where we get in-depth on the entire process of our 100% Kona coffee.
In this post, we'll be taking a closer look at fermentation and the drying process at Ulu Coffee. Last month we explained the washed process employed to process our Kona coffee cherries. And also introduced the pulping machine and that critical metabolic process required to remove all the layers necessary to produce a delicious cup of coffee.
To continue where we left off, that metabolic process is known as fermentation.
Fermentation is the chemical breakdown of a substance by bacteria, yeasts, or other microorganisms that typically give off heat. Fermentation in coffee production is a naturally occurring process where the breakdown of sugar is facilitated by enzymes naturally occurring in the coffee fruit and microflora acquired from the environment.
In other words, this step is how we remove the mesocarp layer (slimy mucilage) from the seed after it is pulped. Temperature, altitude, and moisture are all variables in how a farmer will decide to move forward with this phase and for how long.
If poorly managed or left unattended, fermentation can impart undesirable flavors into the final brew and ruin an entire crop. Because of this, it’s a crucial step. The decisions made here often require a little luck, a lot of patience, and an explicit understanding of the climate and the coffee plant at hand.
What is fascinating is that fermentation is one of the only steps in coffee processing that differs greatly from region to region and even from farmer to farmer. During this phase, important decisions can vary due to geographic location, available resources, and environmental surroundings.
For Ulu Coffee, freshly pulped Kona beans soak iin an open tub of clean water overnight. By doing this, we enable the microbes to eat away at the natural sugars surrounding the seed and, in turn, remove the slimy mucilage layer.
But coffee fermentation is a subject growing in popularity for its scientifically complex effects, and producers are learning more about its impact on flavor. Controlled methods of anaerobic fermentation and experimental batches with added yeasts, like our limited release Kona, Flyin' Blind, are trending throughout specialty coffee and we're here for it.
One can expect refinement, subtle changes or added wine yeasts to our fermentation processes with new single lot varietals to come.
After our beans soak in the fermentation tank for about 18 hours, we wash them vigorously with clean water until they are squeaky clean of their gooey mesocarp layer. Then the beans are wheeled over to the dry shack, a covered A-frame we often refer to as our "Happy Place."
Although most crops from our harvests at Ulu have outgrown our small farm for processing, our beans dry under the shack at Kona Farm Direct, where Kraig Lee and his team traditionally rake the beans every two hours until the moisture content reaches 11%.
With a large handcrafted, wooden rake, they rake the beans are raked around the floor of the shed reiki style with a handcrafted, wooden rake every couple of hours to ensure consistent and even drying among the beans--a common and traditional tactic for premium quality beans.
Once a cup of beans reads 11% in the moisture meter, they're officially Parchment and ready for the dry mill. Parchment is the stage of the bean that immediately precedes green beans. During this stage, the beans contain a flaky parchment and silver skin layer that will need hulling by the coffee Miller before it's sorted, graded, and roasted.
Once parchment is hulled, it’s discarded or used for compost and the beans are graded and sorted. For centuries coffee growers in Kona have looked to maintaining quality, taste, and consistency as essential to keeping a thriving business.
Until recently, Hawaii was the only place in the United States for growing coffee. With the price of growing, farming, harvesting, and processing coffees the U.S., the cost of business is considerably higher than in other, mostly third-world growing regions. Therefore this standard-bearer for quality is needed to survive.
In the late ’80s, the Hawaii Department of Agriculture established a system of grading and evaluating coffee grown on the Islands of Hawaii. The grading system, governed by the Hawaiian Department of Agriculture, qualifies coffees grown by size, moisture content, and amount of defects in a determined sample size.
In Hawaii, beans are primarily graded by size and by the number of defects in a particular sample size. Something that is unique to Hawaii as very few other regions go through the additional time and effort to sort their beans in this way.