If you are curious about coffee like I am, you may be wondering what coffee grading is and what are the different grades of coffee? Do coffee grades tell you about the quality of the coffee? There isn’t a standard universal grading system for coffee, but I am going to explain what the grades are and what they mean.
In general, there are 5 different grades of coffee beans. The beans are graded based on bean size and the percentage of defects they have per batch. The 5 grades are numerical, 1 being the highest quality grade beans and 5 being the lowest.
This is a simple explanation of how coffee beans are graded, but there are more details involved in how the grading takes place. Each country has its own way of grading beans, but the principles for determining the grade are pretty much the same. Keep reading to learn more about how beans are graded and what makes each grade different.
How are coffee beans graded?
Coffee producers grade beans so that each batch contains a consistent size and quality bean. When you go to roast coffee, if some of the beans are large and some are small, they won’t roast evenly. By sorting the beans, each batch of coffee is around the same size and quality. Farmers can still sell the smaller beans, but they will be sold in batches according to their grade.
Overall, coffee beans are graded by their size and the number of defects. Coffee beans are typically sorted in 1/64 inch increments. Then graded by the amount and type of defects they have.
Coffee Beans are First Sorted by Size
Grading beans starts by filtering them through a screen. The screens have holes in them. The holes in each screen are incrementally smaller. Screen sizes range from around size 18 to size 10. The beans that are large enough to remain in the first sorting screen will go on to be inspected for quality. The large beans will receive the highest grade if they pass the quality inspection. Batches with defects will be graded lower, even if they are the right size. The sorting will continue, with each screen filtering resulting in a lower grade.
After the beans are sorted, they are measured by weight. A batch might only contain beans that pass through a certain screen size, but when they are weighed some batches may be lighter in weight than others. This is how they determine the percentage of beans that pass the size criteria in a batch.
The Coffee Beans are Then Sorted by the Type and Number of Defects
When it comes to grading coffee, defects matter as much as size. There are two categories of defects that are used as criteria when grading coffee beans, primary defects, and secondary defects. Primary defects include beans that are black, sour, the cherry is too dry, and batches that contain fungus, foreign matter, or severe insect damage. Secondary defects are not as significant as primary defects, but still, affect the grade of the beans. These include partial black or sour beans, unripe beans, damaged hulls, or beans with mild insect damage.
Grade 1 Coffee
Grade 1 is the highest quality of coffee, generally reserved for specialty coffee. Beans that remain in screen size 17 or higher (depending on the country of origin) are used for grade 1 coffee. No more than 5 percent of the beans contained in the batch can be larger or smaller than the screen size indicated. These beans are not only larger in size, but they can not contain any primary defects. In order to be considered grade one, they can only have a small percentage of secondary defects (no less than 5 defects per 300-gram batch). To be classified as a grade 1 specialty coffee, the beans must also have at least one unique characteristic, such as a distinct body, aroma, acidity, or flavor.
Grade 2 Coffee
Grade 2 coffee beans meet all of the size standards for size 1 beans. They are still large, high-quality beans, but they don’t make the grade when it comes to defects. Like specialty coffees, they need to have a unique characteristic. They can have primary defects and qualify as a grade 2 coffee, but these defects still need to be kept to a minimum. No more than 8 defects can be contained in a 300-gram batch.
Grade 3 Coffee
This grade is where the coffee beans start to go down in size and quality. These beans are considered exchange-grade coffees. Grade 3 beans are screen size 15 or larger. While they are sorted by size like grades 1 and 2, there can be a variation in the size of the beans within the batch. At least 50 percent of the beans in the batch must be size 15 or larger. Each batch can contain no more than 9-23 full defects per 300 grams. While this coffee is allowed to have more defects than grades 1 and 2, it can only contain 5 quakers per batch. A quaker is an unripe or underdeveloped bean. This grade is an inferior coffee, but it’s still considered an acceptable, but lower quality coffee.
Grade 4 Coffee
Anything below grade 4 you want to avoid. Grade 4 coffee is considered below standard coffee. These beans may have less than 50 percent of the batch smaller than size 15 by weight and can have as many as 9-23 full defects per 300 grams.
Grade 5 Coffee
Grade 5 is the lowest quality coffee and is known as off-grade coffee. Grade 5 coffee may have smaller beans, unripe beans, and more than 86 defects in a 300-gram batch.
Things to Consider When Selecting a Coffee Grade
The system of grading coffee varies from country to country. The numbered 5-grade system is based on the system created by the Food and Agricultural Organization of the United Nations. This is the way most coffee is graded, but some countries have their own grading system and names for coffee grades. The criteria for grading coffee are still the same, but the names and criteria for each grade might be different.