Coffee drinkers have never had it so good - especially if they understand the source and qualities of the coffee in their cup. Where coffee is grown, how it is harvested, the roasting process and the water used to make the brew are just a few of the elements that influence the taste of what we drink. Coffee experts James Hoffmann looks at these factors and more. He considers different coffee varieties, the impact of terroir and how coffee is harvested, processed and roasted, through to the way in which the beans are brewed. Country by country - from Bolivia to Zambia - he identifies key characteristics of that area's coffee and also gives practical advice on how to make superb coffee of all kinds at home.