Like an artist creating a perfectly harmonious canvas by using his paint palette, the roaster produces seductive masterpieces in the cup out of single-origin coffees. As old as coffee itself, blending is a technique that optimizes the body, aroma, and flavors of single-origins in order to create new tastes. The goal of coffee blending is to produce a cup of coffee that is superior to each single component alone.
Coffee blending may be done either before or after roasting, and arguments for and against each method exist. For the home coffee chef purposes, blending before roasting makes perfect sense because it is easier and involves smaller quantities.
Filter Coffee Blends
The Melange blend contains a mixture of coffees that have each been roasted to a different degree, including both light and dark levels. This technique allows roasters to mix the robust flavor of a dark roast with the acidic intensity of a lighter-roasted Kenyan or Central American coffee.
The Arabian Mocha-Java, perhaps the oldest and most famous blend, combines an Indonesian coffee with either an Ethiopian or a Yemenite coffee. It is commonly blended using a 2:1 ratio. The full-body Java is combined with the floral-fruity, acidic Mocha coffee to create a more complete and balanced cup. For centuries, these were the only types of coffee in existence.
The goal of an espresso blend is quite different from that of a drip or filter coffee blend. Instead of blending for complexity, which might prove overwhelming using strong espresso extracts, the aim is to blend for balance. Occasionally, an espresso blend will also be used to highlight the specific, varietal quality of a particular bean.
Espresso blends are typically based on Brazilian Arabica coffee. For milk-based drinks, the addition of an African coffee (wine-like acidity or flowery fruitiness) or a high-grown Central American coffee (clean acidity) is common. For straight espressos, I recommend including a Pacific coffee to create more richness, body, and a deep-toned acidity.
Turkish Coffee Blends
The blends used to make Turkish coffee usually include a high percentage of Brazilian Santos Arabica coffee blended with some Robusta or a "secret" ingredient, such as a Colombian, Ethiopian, Harrar or Yemen Mocha coffee. This secondary ingredient serves to enrich the flavor.
Creating Your Personal Signature Blend
First, you should learn how to taste coffee carefully. This means being able to distinguish between acidity, body, and flavor. In addition, you should be able to determine some of the more individual notes a coffee carries, such as the floral tones of Ethiopian coffees, the spicy tones of Sumatras, and the dry, fruity tones of Kenyan origins. You should also know what qualities you prefer in your cup. Once this is clear, purchase a few single-origins from different regions. Then try mixing them in various quantities to enhance the coffee qualities you like and diminish those you dislike.
For example, blending a Brazilian, Central American and Colombian coffee will create a sweet, clear cup. The same blend using a Pacific instead of a Colombian coffee will provide some additional spicy notes. If you wish to add some outstanding tones of fruit, flowers and even chocolate, try including an African coffee. If the coffee becomes too sweet and round, remove the Central American coffee and increase the African coffee. For you, just as for the artesian roaster, cup perfection is the result of a fun process of trial and error.