An Insight into Coffee Processing

Understanding Coffee Processing in the Food Industry

Coffee, scientifically known as Coffea sp., is a premium plantation crop widely used in specialty beverages. Whether it’s a hot cappuccino, latte, cold brew, or Frappuccino, coffee is cherished worldwide. The primary reason behind coffee’s popularity is its caffeine content, which provides a stimulating effect. Additionally, it contains bioactive compounds like chlorogenic acid, trigonelline, and nicotinic acid, offering various health benefits. Most coffee consumers understand that coffee is a bean ground and brewed into a beverage, but few know about coffee cultivation, harvesting, and processing techniques. This article provides an in-depth insight into coffee processing, from farm to cup.

The Botany of Coffee Plant

The coffee plant belongs to the Rubiaceae family and grows best at altitudes of 600–1200 meters with an annual temperature of 15–25°C. It thrives in moderate moisture and cloudiness. The plant bears fragrant white flowers and produces cherry-like fruits, which house the coffee beans. The two main commercial coffee species are:

Coffea arabica (Arabica) – Includes varieties like Bourbon, Typica, Caturra, Mundo Novo, Tico, and Jamaican Blue Mountain.
Coffea canephora (Robusta) – Known for its strong flavor and higher caffeine content.

The Anatomy of Coffee Cherry

A coffee cherry consists of multiple layers:

Exocarp – The outer skin.
Mesocarp – A thin layer of pulp.
Parenchyma – A slimy protective layer.
Endocarp (Parchment) – A paper-like envelope covering the coffee bean.
Silver skin – A thin protective covering of the bean.

Harvesting of Coffee

Coffee is generally harvested between November and February, depending on the variety. Harvesting methods include:

Fly Picking – Initial selective handpicking of ripe coffee cherries.
Main Picking – Fully ripened cherries harvested 4–6 times at 10–15-day intervals.
Stripping – Final harvest, where all remaining cherries are picked.
Cleaning – Collection of fallen cherries.

Processing of Coffee

After harvesting, coffee undergoes two primary processing methods: wet processing and dry processing, based on the required coffee type.

1. Wet Processing (Parchment Coffee Production)

Cherries are pulped to remove the outer layer.
Beans undergo fermentation and washing to remove the mucilage.
Sun drying/tray drying for 1–2 days.
Requires careful monitoring to avoid contamination due to over-fermentation.

2. Dry Processing (Cherry Coffee Production)

Whole cherries are sun-dried/artificially dried for 12–15 days.
Beans are hulled and winnowed.
Considered more eco-friendly but time-consuming.
Proper drying ensures premium flavor and aroma.

Roasting of Coffee

The roasting process is crucial as it determines the color, aroma, and taste of coffee beans. Drum/hot air roasting typically occurs at 200°C for 15–20 minutes. There are four major coffee roast types:

Light Roast – Mild flavor, high acidity.
Medium Roast – Balanced flavor, popular choice.
Medium-Dark Roast – Richer taste, slight bitterness.
Dark Roast – Strong, bold flavor, lowest acidity.

Grading, Sorting, and Packaging of Coffee

After roasting, coffee beans are ground in rolling mills for a smooth texture. Arabica and Robusta beans are classified as washed (parchment/plantation) and unwashed (natural). Further grading is based on bean size, imperfections, and quality:

Coffee Grading System

Grade 1: Specialty Grade – No defects, distinct attributes.
Grade 2: Premium Grade – Minor imperfections.
Grade 3: Exchange Grade – Must meet minimum quality standards.
Grade 4: Standard Grade – Moderate defects.
Grade 5: Off-Grade – High level of defects.

Coffee Packaging Methods

Ground coffee – Glass jars or paper bags.
Whole beans – Jute bags, sacks, or paper bags.

Why Coffee Processing Matters for Food Industry Consulting

Coffee is more than a beverage — it's a sophisticated, multi-stage food manufacturing process that requires a combination of technical design, compliance, and operational planning. PMG Engineering, a leader in food consultancy services, offers expert solutions in coffee plant design, equipment integration, and supply chain planning.

Whether you’re an entrepreneur looking to set up a new coffee brand or a manufacturer scaling operations, working with a trusted food consultant ensures efficiency, compliance, and product quality.

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