Jamaica Blue Mountain Coffee Grades: No. 1, No. 2, No. 3 and Peaberry

Jamaica Blue Mountain coffee is graded mainly by bean size and defect count. The classes usually quoted are Blue Mountain No. 1, No. 2 and No. 3, a separate peaberry class and a mixed "triage" class, and buyers most often see "No. 1" or "Peaberry" on retail bags.

How is Blue Mountain coffee graded?

Like most washed arabicas, Blue Mountain coffee is sorted after milling through perforated screens. Screen sizes are measured in 64ths of an inch, so a bean retained on a screen 17 is roughly 17/64 of an inch across, and a "17/20" description means the beans fall within screens 17 to 20. Beans are then inspected for defects such as black, sour, broken or insect-damaged beans.

A widely reproduced summary of the classes, attributed to Jamaica's coffee industry regulations and published by the long-running importer Cafe Kingston Jamaica, sets them out as follows. Wikipedia's article agrees on the overall structure, three size grades plus peaberry, without giving screen numbers.

One caveat: the JACRA regulations published in the Jamaica Gazette in 2018 define the protected names and the licensing system, but their text does not list screen sizes. Some retailers describe No. 1 as screen 17/18 rather than 17/20. Treat the table as the trade's standard description rather than a quotation of current law, and rely on the exporter's paperwork for any specific lot.

What is Blue Mountain peaberry?

A peaberry forms when a coffee cherry develops one rounded seed instead of the usual two flat-sided ones. It is not a separate variety or a separate farm; peaberries turn up in ordinary Blue Mountain harvests and are sorted out because their shape roasts differently. Wikipedia describes Blue Mountain peaberries as smaller and rounder than the flat beans. Because they are sorted into their own class, peaberry lots are sold and usually priced separately, much as with Kona peaberry.

What counts as a defect?

Defects are beans that are visibly damaged or poorly processed: black or sour beans, broken pieces, insect damage, shells and foreign matter such as stones or sticks. Jamaica's 2018 regulations attack some of these at the source. Regulation 18 bars anyone from picking, selling or buying, for commercial purposes, coffee containing entirely green berries, black berries mixed with stones or trash, coffee dried in the double husk, or coffee not dried to JACRA's standards. Grading then removes what remains after milling. Coffee berry borer damage, a problem in Jamaica since the beetle was detected in 1978, according to a 2023 study in Insects, is one reason hand sorting still matters.

How do Blue Mountain grades compare with other origins?

The comparison shows how differently origins draw their lines: Hawaii counts defects per sample weight, while the Jamaican summary uses percentages. None of these grades is a flavor score, and none says anything about how fresh the coffee is when it reaches a cup. They are best read as minimum standards for size and cleanliness that let buyers on opposite sides of the world trade a lot without inspecting every bean.

Is a higher grade better coffee?

Not automatically. Grading is a size and cleanliness standard. Larger, more uniform beans roast more evenly and a low defect count removes obvious flaws, so No. 1 is a sensible floor for a premium bag, but grade alone does not describe acidity, body, sweetness or freshness. A well-roasted No. 2 can taste better than a stale No. 1. The same is true of other origins that grade by screen size, such as Kenya's AA system or Colombia's Supremo and Excelso.

Grades also say nothing about authenticity. Anyone can print "Grade 1" on a bag. What matters for authenticity is whether the coffee is Jamaica Blue Mountain under the 2018 regulations, grown in the defined area and traded under JACRA licence, and whether the bag is 100% Blue Mountain or a blend that may be 70% something else.

How does grading fit into certification?

Grading is one step in a longer chain. WIPO's case study describes the traditional process: ripe cherries are selected and pulped, wet parchment reaches an authorized facility within 24 hours, the coffee is sun-dried and rested for at least eight weeks, then hulled, polished and hand-sorted before certification. The 2018 regulations require dealers to record, where applicable, the grade, type and quality of every lot they buy or sell, and export coffee stays in JACRA's custody until it ships. Our JACRA certification page covers that system.

What should a buyer look for on the label?

• "100% Jamaica Blue Mountain" first. A grade on a blend bag only describes the Blue Mountain portion, which can be as little as 30%.
• The grade or "Peaberry", if stated. Many retail bags do not state a grade at all, which is not in itself a warning sign.
• A named roaster, estate or exporter in Jamaica, and a roast date. Grade cannot make up for old coffee.

For green-coffee buyers, our page on buying and storing unroasted coffee explains how size and moisture affect roasting. Back to the overview: Jamaica Blue Mountain coffee.