The Home Barista (The Experiment, 2015) by Simone Egger and Ruby Ashby Orr teaches readers the ins and outs of brewing their favorite cup of coffee right at home. Egger and Ashby Orr walk readers through eight different methods of brewing after roasting your own beans. In this excerpt, they explain how coffee beans are made from the fruit of a coffea tree.
Beans for Botanists
Going back to the beginning, coffee beans are actually seeds found inside the bright red, cherry-like fruit of a coffea tree. There are different species of coffea tree, but generally, they grow to around ten feet and flourish in tropical conditions (hot and high), between the tropics of Capricorn and Cancer.
The coffea tree blooms fragrant, white flowers three times a year and the cherries begin to grow after each bloom, reddening from green as they ripen. Each cherry contains two green seeds that, once processed, become what we know as coffee beans.
Arabica vs. Robusta
Arabica is the species of plant from which all specialty (and also most commercial) beans are currently derived. It’s a princess of plants: fragile, susceptible to attacks by pests and relatively needy—requiring particular degrees of moisture, sun, shade and soil richness to thrive. But, it’s also capable of producing a wide taste range. There are a number of varieties, strains and cultivars of arabica.
Robusta is the other species that’s commercially farmed. It’s just beginning to emerge onto the specialty coffee market, but is commonly used in instant coffee brands. It’s a hardier plant with a higher yield of beans that are higher in caffeine but have been described as having “a neutral to harsh taste range.” Still, a small number of coffee growers are experimenting with specialist robusta—time will tell if it catches on.
It takes a lot to turn a cherry into a coffee bean. After it’s picked, often by hand (one cherry at a time), the raw fruit is processed to remove the cherry pulp from the seed (or bean). There are various ways to do this.
The most meticulous process, which requires custom equipment, is wet processing (also referred to as washed coffee), where the pulp is allowed to ferment before being washed off, then the bean is dried and hulled to remove the parchment around the seed.
Another commonly used process is the dry process (also known as natural coffee), where the whole fruit is dried and then hulled, which removes the parchment and pulp in one process.
There is a third, in-between process called semi-drying (sometimes called semi-washed, or wet-hulled) in which the pulp is removed by custom-built machines, before the seeds are stored for a day, washed, then partially dried.
Once the bean has been completely separated from the fruit, it’s cleaned and sorted according to its density, size and color, then graded.
More from: The Home Barista• Roasting Your Coffee Beans at Home
• Knowing Your Coffee Ethics
Excerpt from The Home Barista: How to Bring Out the Best in Every Coffee Bean, copyright © Simone Egger and Ruby Ashby Orr, 2015. Reprinted by permission of the publisher, The Experiment. Available wherever books are sold. theexperimentpublishing.com.