A spec sheet is the shortest honest conversation you can have with a coffee before it arrives. One page, a dozen fields, and a promise about what is sitting in the bags. For a roaster or importer, learning to read it fluently is the difference between confident purchasing and hoping the sample matches the shipment.
The trouble is that spec sheets look deceptively simple. Numbers, a few descriptors, a score. But each field answers a specific commercial question, and knowing which question turns a wall of data into a decision. Here is how to read every line the way an experienced buyer does.
Origin, Varietal and Crop Year
The top of the sheet establishes identity: country, region, producer or estate, varietal, and crop year. These are the anchors everything else hangs from.
Varietal tells you the genetic starting point. Bourbon, Typica, SL varieties, Catuai, Caturra and hybrids each carry tendencies in cup character, yield and disease resistance. A varietal is not a guarantee of flavour, but it sets expectations and helps you compare like with like across seasons.
Region and producer matter for traceability and consistency. A named estate lot behaves differently from a regional blend of many smallholders; the former is easier to re-order with confidence, the latter often offers volume. Neither is better in the abstract, they simply suit different programs.
Crop year is quietly one of the most important fields. Green coffee is agricultural, not shelf-stable. A current-crop lot will generally show brighter acidity and cleaner aromatics than a past-crop one that has spent months in a warehouse. If a sheet omits the crop year, ask. It changes how the coffee will taste on your roaster in three months.
Altitude and Process
Altitude is usually given as metres above sea level (MASL) as a range. Higher-grown coffees tend to develop more slowly, producing denser beans and, often, more complex acidity. It is a strong signal but not a rule; local climate and shade can shift the picture. Use altitude to predict density and to set your roast expectations, not as a marketing badge.
Process describes how the fruit was removed from the seed: washed, natural, honey or pulped natural, and their variations. Washed coffees typically read cleaner and more transparent to origin. Naturals bring more body and fruit-forward intensity. Honey processes sit in between. Process affects not just flavour but also how the coffee stores and how forgiving it is on the roast curve, so it belongs in your planning from the start.
Harvest window tells you when the cherries were picked. Combined with crop year, it lets you estimate how fresh the green will be on arrival and how long you can reasonably hold it before quality drifts.
The Physical Grade Fields
This is the block that spooks newer buyers, and it should not. These numbers describe the physical condition of the beans.
Screen size measures bean dimensions using round-holed screens sized in 64ths of an inch. A "screen 17/18" lot has larger, more uniform beans than a "15/16" one. Uniformity matters more than size itself, because evenly sized beans roast evenly. A wide screen spread hints at inconsistent roasting and more work dialling in.
Moisture content, expressed as a percentage, typically sits in the 10 to 12 percent band for well-prepared coffee. Too high and you risk mould, fermentation faults and rapid ageing in the bag. Too low and the coffee may have been over-dried or aged, often reading flat in the cup. The number itself matters less than whether it falls in the safe, stable range.
Water activity (aw) is moisture's more sophisticated sibling. It measures the free, available water in the bean rather than total moisture, on a 0 to 1 scale, with well-prepared green coffee commonly around 0.55 or below. It is a strong predictor of storage stability and shelf life. Two lots can share the same moisture reading yet age very differently if their water activity diverges, which is why serious buyers now watch this field closely.
Density, often given in grams per litre, reflects how hard and compact the beans are. Denser beans generally correlate with higher-grown coffee and need more energy to roast. Knowing density up front helps your roasting team plan the approach rather than discover it mid-batch.
Defect Count, Grade and Cupping
Defect count and grade quantify physical flaws: black beans, broken pieces, insect damage, stones and other foreign matter, counted against a standard to assign a grade such as Specialty Grade or a Grade 1/2 designation. Fewer defects means a cleaner cup and less loss during sorting. This is a measure of preparation care as much as raw quality.
Cupping score is the headline number, most commonly on the 100-point scale where 80 and above denotes specialty. But the score without the cupping notes is half a sentence. The notes describe the sensory profile: acidity, body, sweetness, and specific flavour descriptors. Read them together. An 85 described as "juicy, red fruit, clean finish" tells you something a bare "85" never could, and it lets you check whether the coffee fits your blend or single-origin slot.
Red Flags to Watch
A few patterns should make you slow down and ask questions:
- Missing crop year or harvest date. Ageing is the most common hidden problem in green coffee.
- Moisture above roughly 12.5 percent, or water activity creeping toward 0.65. Both raise storage and quality risk.
- A high cupping score with vague or absent notes. Numbers are easy to type; a specific sensory description is harder to fake.
- A wide screen-size spread on a "premium" lot. It signals uneven preparation.
- Round numbers everywhere. Real measurements rarely land on tidy figures across every field.
None of these are automatic dealbreakers, but each deserves a straight answer before you commit.
Reading With Confidence
A good spec sheet is not a sales document, it is a set of testable claims. The fields connect: altitude hints at density, process shapes the cup, moisture and water activity predict how long the quality lasts. Once you read them as a linked story rather than isolated numbers, evaluating a new offer becomes fast and calm.
At Caffeine Nirvana we publish full lot documentation for our Chikmagalur green coffees so buyers can check every figure against their own cupping table. Whoever you source from, the habit is the same: read the sheet, request the sample, and let the two tell one consistent story before the container ships.