Coffee Tree Basics and What Determines Caffeine Levels

If you’ve ever wondered why your cup of coffee tastes the way it does—or why some coffees have more kick than others—the answer starts with the coffee tree. From the height growers keep their trees to the color of the beans inside each cherry, a surprising number of factors influence what ends up in your brew. Here’s what you need to know, straight from the plant to your espresso.

The coffee plant belongs to the Rubiaceae family (like gardenias), was scientifically named ‘Coffea’ by Swedish botanist Linnaeus, and produces the cherries we turn into coffee. Most cultivated coffee trees are kept between 3–5 meters tall to make harvesting easier—except in Colombia, where they grow to just 2 meters. Each coffee cherry typically holds two seeds (the beans), surrounded by layers including a silvery skin, and their final size, color, and flavor vary by variety.

What Are Coffee Trees and How Are They Grown?

Coffee plants (genus Coffea) are small evergreen trees or shrubs native to tropical regions. In the wild, they can reach 10–12 meters, but in cultivation they’re pruned to 3–5 meters for manageability—with the exception of Colombian plantations, where trees usually don’t exceed 2 meters. Leaves transition through shades of deep green, light green, and bronze-yellow during growth cycles. The small, jasmine-like white flowers appear in clusters and later give way to red (or sometimes yellow or purple) coffee cherries.

Each cherry looks much like a small cherry and contains two flat, bean-shaped seeds lying pressed together. These are coated in a sticky, sweet pulp (mesocarp), covered by a thin outer skin (exocarp). Inside, each seed is protected by a tough, golden-yellow layer called parchment (endocarp), and beneath that lies an extremely thin silver skin. The actual green coffee bean ranges from blue-green to bronze, usually 8–11 mm long and 6–8 mm wide. Varieties differ in size, shape, color, and resistance to pests and disease.

Arabica vs. Robusta: The Two Main Coffee Species

Today’s commercial coffee production centers on two main species: Arabica and Robusta.

• Arabica (Coffea arabica): Accounts for about 75% of global production. Originating from the Arabian Peninsula, it thrives at higher altitudes (600–2200m), prefers rich, volcanic soils, and grows best between 15–25°C. Well-known Arabica cultivars include Bourbon, Typica, Mocha, Maragogype, San Ramon, and Columnaris. It has a smoother, more nuanced flavor, lower caffeine content, and beans that appear oval and bluish-green. Brazilian Arabica is widely traded as ‘Brazilian coffee’, while beans from Central America and the Caribbean are known as ‘Milds’. Some African countries also produce high-quality Arabica.
• Robusta (Coffea canephora): Makes up around 25% of the world’s coffee. It was discovered in the Congo in 1898 and is hardier, growing at lower altitudes (0–600m), with greater pest resistance and faster maturation. Robusta trees can exceed 12 meters. Its beans are smaller, rounder, and yellow-brown, with roughly double the caffeine of Arabica (about 2.7% vs 1.5%). Robusta offers a stronger, harsher cup with more bitterness and a distinctive woody or earthy tone—especially apparent in lower-quality or poorly processed examples. Washed Robustas from Indonesia are rarer and more prized. It’s commonly used in espresso blends for body and crema enhancement.

Where and How Coffee Grows Best

Coffee requires very specific growing conditions:

• Climate: Tropical or subtropical regions within 23.5°N and 23.5°S latitude, with consistent rainfall and temperatures between 15–25°C. Humid, mild conditions are ideal.
• Soil: Deep, well-drained, loamy or volcanic soils with good structure and permeability. Ideal locations are hillside slopes, often on volcanic or forested terrain.
• Altitude: Best growth occurs between 600–1200 meters. Some varieties thrive up to 2000–2200m, while others grow well below 400m or even at sea level.

From Flower to Harvest: Coffee Cultivation Steps

Growing coffee is a long process:

• Seeds are selected from healthy, productive mother trees.
• They’re germinated and raised in shaded nurseries for around six months.
• Young seedlings are transplanted to fields during the rainy season, still with their root balls intact.
• In some regions, coffee is intercropped with shade trees to protect it from wind and sun.
• Trees typically begin fruiting at 3–4 years old.

How Coffee Cherries Are Harvested

Harvest timing depends on location, altitude, and climate, and occurs at different times of year by region. Ripe cherries can be picked by hand (selectively or strip-picked), using small tools, or—in flatter areas—by mechanical harvesters. Selective picking (hand-picking only ripe cherries) yields higher quality but is labor-intensive. Mechanical stripping is faster but gathers unripe and overripe fruit, requiring further sorting.

Coffee Processing Methods

After harvest, coffee must be processed quickly to avoid spoilage. There are two main methods:

• Dry/Natural Process: Common in Brazil and West Africa. Whole cherries are spread in the sun and turned regularly for 15–20 days until fully dried. The outer layers dry around the beans, which are later hulled.
• Wet/Washed Process: Used in Central America, Colombia, Kenya, and Tanzania. Cherries are washed, pulped to remove the outer skin, fermented to break down the mucilage, then washed again, and dried on patios or raised beds. This method results in ‘washed’ or ‘bright’ coffees with cleaner flavors and higher acidity.

After drying, beans are hulled to remove the parchment, polished (optional), sorted, and bagged in 60kg jute sacks for export.

What Is Espresso and How Does It Relate to Coffee?

Espresso is not a bean type but a brewing method: coffee brewed under pressure (9 bar) for a short time (25–30 seconds), producing a small, concentrated shot. Good espresso features a rich crema (foam layer), extracted oils, and dissolved solids including caffeine, sugars, and acids. Around 80–85% of the caffeine is extracted, but due to the short brew time and smaller serving size, a single espresso often contains less caffeine than a cup of drip coffee.

Espresso blends are carefully crafted, often combining 5–6 or more origins. Pure Arabica blends tend to be softer and aromatic, while Arabica-Robusta blends offer more body and intensity. The best espressos are medium to dark roasted, balancing sweetness, acidity, and bitterness. Crema plays a key role in aroma retention and mouthfeel.

Decaffeination: How Low-Caffeine Coffee Is Made

Caffeine is the main bioactive compound in coffee, with a typical cup containing 50–150mg. Several methods can remove most of it while trying to preserve flavor. One early method used steam and solvents to extract caffeine through the bean’s porous structure.

By EU law, decaffeinated coffee must contain less than 0.1% caffeine in the green bean stage. All commercial decaf processes must meet strict regulatory thresholds. Despite common belief, some decaf methods can produce excellent flavor, especially when high-quality beans are used.

Lavazza Blends: Examples of Different Coffee Profiles

The article profiles several Lavazza specialty blends, illustrating different roast levels, origins, and flavor goals:

• PIENAROMA: 100% Arabica, medium roast, smooth and delicate with floral and fruity notes.
• GOLD SELECTION: Mild Arabicas with a touch of Robusta, medium roast, balanced and creamy.
• GRAND’ ESPRESSO: Robusta-Arabica blend, medium roast, intense and bold with chocolate notes.
• LAVAZZA IN BLU: 100% Arabica, designed for home espresso machines, aromatic and rich.
• CREMA E AROMA: African, Asian, and South American blend, medium roast, spicy and full-bodied.
• DEK: Low-caffeine blend of Brazilian and Asian beans, medium-dark roast, creamy and balanced.
• Qualità Oro: Popular Italian blend with Brazilian and African beans, chocolatey and milk-friendly.

Frequently Asked Questions

What family does the coffee plant belong to?

The coffee plant is part of the Rubiaceae family, the same family as gardenias. It was classified under the genus Coffea by Swedish botanist Linnaeus.

How tall do coffee trees grow?

In the wild, coffee trees can grow up to 10–12 meters, but cultivated trees are usually kept between 3–5 meters tall for easier harvesting. In Colombia, they typically don’t exceed 2 meters.

What are the two main types of coffee beans?

The two primary commercial coffee species are Arabica and Robusta. Arabica accounts for around 75% of global production and is known for its smoother flavor and lower caffeine. Robusta makes up about 25% and has stronger, harsher taste with almost double the caffeine content.

What’s the difference between the dry and wet coffee processing methods?

The dry method, or natural process, involves drying whole coffee cherries in the sun for 15–20 days, while the wet method, or washed process, removes the cherry skin and ferments the beans before drying. Wet-processed coffee tends to have a cleaner, brighter flavor, whereas dry-processed coffee is often fruitier and heavier.

How much caffeine is in a typical cup of coffee?

A regular cup of coffee contains between 50–150mg of caffeine, depending on bean type, brew method, and serving size. Espresso has higher caffeine concentration but usually less total caffeine per serving due to smaller volume.

What is considered low-caffeine coffee?

By EU regulations, decaffeinated coffee must have less than 0.1% caffeine in the green bean. Decaf processes aim to reduce caffeine while preserving as much flavor as possible, and some methods can produce high-quality low-caffeine coffee.

Recommended FrontStreet Beans for Coffee Tree Enthusiasts

Explore the origins behind your cup with FrontStreet Coffee’s Ethiopia Yirgacheffe, known for its bright acidity and floral notes, and Honduras Finca La Esperanza, a balanced Washed Arabica with citrus and caramel. For something bolder, try Sumatra Mandheling, a classic Robusta-influenced full-bodied blend. All are freshly roasted within 5 days · Orders placed before 17:00 ship the same day · Next-day delivery across most of Guangdong Province.