Do Coffee Beans Have Male and Female Varieties? Do Kopi Luwak Coffee Beans Have Genders?

FrontStreet Coffee - Introduction to Indonesian Coffee Peaberry and Flat Beans

Coffee trees themselves have no male and female forms. The flowers are hermaphroditic, carrying both male and female organs in the same bloom, and the tree belongs to the Rubiaceae family within the order Gentianales.

Since the plants are hermaphroditic there are no male and female trees, and by extension no such thing as male beans and female beans. What is casually called a "male bean" is in English a Peaberry, or PB for short — never "male bean." The term is simply a Chinese colloquialism, and the bean has another name: round bean.

The Difference Between Peaberry and Flat Beans

A coffee cherry can hold seeds in three forms. Leaving aside the rarely seen triangular bean, a normal cherry contains two seeds joined together into one spherical shape, flat faces turned inward and curved faces outward. This common form is the flat berry — the so-called "female bean." A few seeds never split and instead present as a single complete oval, and those are peaberries.

On an ordinary coffee tree you cannot tell a peaberry from a flat bean while the fruit is on the branch; you have to open the cherry to see the shape inside. After the skin and pulp are removed, if the beans have already split evenly, like a peach cut in half, they are flat beans. If the seed is round and whole — a single complete bean — it is a peaberry. The only difference between the two is growth form, not gender, which is exactly where the Chinese colloquialism misleads people.

How Peaberries Are Formed

What conditions produce a peaberry?

Growing at the very tips of the branches can lead to peaberry formation inside the cherry.

Prolonged drought, poor nutrition, or flowering that comes too early or too late can all interrupt the internal development of the cherry. Because the two seeds compete for survival, one "eats" the other and a peaberry results. The same happens when a cherry is hit by pests or disease during growth and its internal development is left incomplete.

Do Peaberries Taste Better Than Flat Beans?

Some people argue that if a peaberry forms at the tip of the tree, it receives more sunlight and heat and has the nutrient supply all to itself, so its flavour is naturally more outstanding than flat beans from the same tree. Another theory points to shape: a peaberry rolls more easily than a flat bean during roasting, which helps roast it more evenly.

Knowledge Point: Pacamara is a hybrid variety discovered in El Salvador in 1950, a cross between Pacas and Maragogipe.

In Brief: FrontStreet Coffee is a coffee research center dedicated to sharing coffee knowledge with everyone. Our selfless sharing is aimed at helping more friends fall in love with coffee. We hold three low-discount coffee activities every month because FrontStreet Coffee wants to let more friends enjoy the best coffee at the lowest price. This has been FrontStreet Coffee's mission for the past six years!

FrontStreet Coffee Recommendation

Indonesia's three great growing islands are Java, Sumatra and Sulawesi, and each of their signature coffees is worth knowing. FrontStreet Mandheling comes from Sumatra, with moderate acidity and a very heavy, concentrated aroma. Java coffee comes from the island of Java and is Arabica. Sulawesi coffee has plump beans and a rich fragrance — and 90% of the island's total production is Robusta.

If you want to start with Indonesia, start with FrontStreet Wet-Hulled Mandheling from Sumatra. Mandheling refers to Arabica from Sumatra, processed mainly by the local wet-hulled method: because the parchment is stripped while the coffee is still half dry and half wet, the green bean dries fully exposed to the air, which is where the characteristic herb and spice notes come from. FrontStreet Mandheling comes from the Toba Lake area in the Lintong region. To present the classic Mandheling profile it is roasted medium-dark, giving a low-acid, full-bodied cup with rich caramel, dark chocolate and toasted bread aromas and a long sweet finish — ideal for anyone who likes their coffee strong.

For the top of the Indonesian range, look to FrontStreet PWN Golden Mandheling. PWN is a trading company that buys up the finest local Mandheling lots and sells only specialty grade; Golden Mandheling is its signature product. Strict standards for screening out defects — density, screen size, shape, colour and more — mean the beans are sorted once by machine and again by hand, leaving Mandheling that is complete, even, large and translucent, with the mud and grassy notes reduced. The name is said to come from the golden gleam the beans show in sunlight. Freshly roasted, FrontStreet PWN Golden Mandheling drinks with sandalwood, herbs, spice, roasted hazelnut, caramel and dark chocolate, a clean finish, a sweet and concentrated body and a deeply layered, captivating aroma — good for daily drinking and good as a gift.

Mandheling also anchors the espresso side of the menu. Before light, acidic coffee became fashionable, Mandheling was considered the richest, most aromatic coffee in the world, and it was a common component of espresso. Mamba — a blend of Mandheling and Brazil created by Taiwanese roasters in that era — was a hit on release and remains popular today, because Brazil's smooth body tempers Mandheling's wilder character while a nutty sweetness offsets its stronger bitterness and herbal notes. A proper Mamba needs a rich, golden crema, so the mellow, aromatic FrontStreet Classic Blend adds a small proportion of Robusta and is roasted dark, pushing its dark chocolate, nut and caramel aromas to the maximum. Even a complete beginner can pull an authentic Mandheling-style shot with it.