Processing Coffee Parchment
It takes 1.25 pounds of dried parchment to produce one pound of green bean coffee.
Coffee processing is a long journey and one of the key steps in that journey is the removal of the coffee parchment, a thin layer that surrounds the coffee bean. This step is often referred to as “hulling” and is critical in preparing the beans for roasting.
The Parchment in Coffee Processing
After the coffee cherries are picked they are pulped to remove the outer skin and some of the fruit flesh leaving the beans surrounded by a protective layer called parchment. This parchment layer along with a small amount of mucilage helps to protect the beans during the drying process. Proper drying is key to prevent mold and fermentation which can ruin the flavour of the coffee.
During the drying phase the parchment becomes brittle and can be removed. The parchment covered beans are now referred to as “parchment coffee” and are spread out on drying beds or patios and left to dry in the sun. This can take several days to weeks depending on the climate and weather. It’s important to monitor the moisture levels during this period to ensure the beans reach the ideal moisture content of 10-12%. Once the beans are dry they are ready for the next step.
Hulling: Removing the Parchment
Hulling is the process of removing the parchment from the dried coffee beans. This is done at a dry mill where machines crack the parchment without damaging the beans inside. Hulling must be done with care as any damage can cause defects in the final roasted coffee.
After hulling the beans are often sorted by size, weight and density to ensure uniformity in the roasting process. The beans are then graded and inspected for quality before being packed for export or roasting.
The Parchment Removal Matters
Removing coffee parchment is more than a mechanical process; it’s a critical step that affects the final product. Proper hulling preserves the bean’s structure and prevents defects. And careful handling during this phase helps to preserve the coffee’s flavour profile so the beans get to the roaster in the best possible condition.
The parchment removal process shows the attention to detail and skill required at every stage of coffee production. From the cherry to the roast every step matters in the coffee we drink in our cups.
The Process of Grading Coffee Explained
– Dried parchment is delivered to the Dry Mill where the parchment skin is removed by a gentle hulling process.
– The coffee beans, now referred to as green bean, are then separated into categories of bean size.
– They are then graded according to density by running over an Oliver gravity table. This ensures that only the perfectly formed beans are bagged and certified.
This process is called grading the coffee and is dictated by a strict set of guidelines administered by the Hawaii State Department of Agriculture.
