Body in coffee is the sensation of weight and texture that is felt while drinking. It is something we feel in our mouth when we are drinking coffee rather than something we can taste.
You will normally use terms such as - it coats your mouth with a lingering, buttery sensation or is it light and delicate.
It is one of the categories used to complete sensory evaluations of coffee, along with other categories such as aroma, sweetness, flavour, acidity, aftertaste, and balance.
During extraction, soluble compounds, such as caffeine, acids, lipids, sugars, and carbohydrates, will dissolve into water. However, insoluble compounds in proteins and fibres, specifically the oils in these, do not dissolve and contribute to the body of the coffee.
During roasting, high pressure from heat forces oils from the centre of the beans, outwards. The longer a bean is roasted, the more physical and chemical changes that occur, including the movement of oil compounds. Therefore, darker roasts generally have an oilier exterior, which can result in a heavier body.