Impact of mug shape and beverage volume on instant coffee perception

The objective of the study was to quantity by descriptive analysis the impact of mug shape (Short/Wide vs. Tall/Narrow) and beverage volume (100, 150, 200 and 250 ml), systematically combined to obtain eight conditions, on the perception of instant coffee. To obtain exhaustive conclusions, the experiment was repeated with four coffee types prepared by combining two coffee species (pure Arabica and pure Robusta) and two powder concentrations (0.8 g/100 ml and 1.6 g/100 ml). The 32 beverages (8 conditions × 4 coffee types) have been profiled sequentially by 11 trained assessors using a glossary of 59 attributes covering appearance, orthonasal aroma, retronasal aroma, taste, mouthfeel and aftertaste perceptions. Results show that conditions significantly impact darkness intensity of all coffee types but high dosed Robusta. This modulation of darkness is not associated with any other significant modulation of perception, except for low dosed Arabica, for which significant changes in darkness are associated with significant changes of four orthonasal attributes (overall aroma intensity, aroma complexity, roasty and malty). It is noteworthy for coffee industry to observe that sensory quality of reconstituted instant coffee was stable across mug and volume conditions for three coffee types. Nevertheless, for low dosed Arabica, the different conditions modulated ortho-nasal perception of aromatic notes probably through crossmodal interactions induced by changes in liquid coffee darkness intensity. Coffee professionals thus need to take into consideration that coffee mugs and cups may affect consumers' perception of certain coffee types.