coffee blends
A "coffee blend" is generally referred to as a mixture of coffee beans made up of different roasts, styles, or tastes of coffee. Although a coffee blend can also be referred as a coffee drink , containing flavoured syrups or other sorts of additives designed to change the taste of the product completely. Mixtures can be made of beans of different roasts, different varieties , or different flavour profiles.
Looking for consistency
Large scale coffee companies and cafes will often market "signature" coffee blends which you will find the same in any shop throughout the world. It is often difficult to achieve a good consistency in the coffee blend from place to place over a span of time. Coffee beans tend to vary by season; times that are wet and fertile produce different tastes to those that are dry or cold.
Flavour concerns
A coffee blend may also be an opportunity to create a unique flavour combination and taste profile. Not only does the coffee's taste depend on where the bean comes from, the process of roasting also matters. The roasting can be very light producing a light "blonde" style drink, or longer which will create more complex Smokey flavours.
Specific uses
Occasionally coffee's are mixed in order to make them ideal for specific purposes. For example expresso blends are a good style of coffee that is generally quite strong and bitter. There are no specific expresso blends that grow, although, coffee that is sold under the name "expresso" is almost always a blend of the darkest, strongest beans and roasts available.
Different types of coffee beans
There are two kinds of coffee beans, Arabica and Robusta. Each have there own distinct characteristics although are grown differently. Arabica beans are grown at high altitudes and are believed to be of the highest quality, even though they have quite a range of tastes and growing areas. However Robusta beans by comparison are grown at lower altitudes and usually have a much stronger flavour. This bean is generally used in making instant coffee and lower grade commercial brews. Robusta beans are also much more circular, whereas Arabica are more oval as shown in the picture to the left.