Coffee is prepared by the extraction of a complex array of organic molecules from the roasted bean, which has been ground into fine particulates. The extraction depends on temperature, water chemistry and also the accessible surface area of the coffee. Here we investigate whether variations in the production processes of single origin coffee beans affects the particle size distribution upon grinding. We find that the particle size distribution is independent of the bean origin and processing method. Furthermore, we elucidate the influence of bean temperature on particle size distribution, concluding that grinding cold results in a narrower particle size distribution, and reduced mean particle size. We anticipate these results will influence the production of coffee industrially, as well as contribute to how we store and use coffee daily.

The present study investigated whether consumers' expectations and perceptions concerning milk-based coffee drinks would be influenced by: (1) the presence/ absence of latt e art on the froth of the coffee, and (2) shape-taste symbolism (i.e., angular versus rounded shapes presented on the froth). An online survey conducted using photographs of cups of coffee revealed that the presence of latt e art did indeed influence people's expectations concerning the value of the drink. Follow-up research revealed that people were willing to pay more for a milk-based coffee drink that had latt e art as compared to a similar drink served without art. In a third experiment, an online survey revealed that an angular shape, relative to a more rounded shape, influenced people's expectations concerning the likability, bitterness and quality of the drink. A final experiment (Experiment 4) revealed that shape influenced people's perception of the quality and estimated price of the coffee. Taken together, the various results reported here demonstrate that the presence of latt e art influences how much people expect, and are willing, to pay for a caf e latt e. As such, adding art to, and the type of visual design on, a customer's drink should be considered by those serving caf e latt e as an effective means of increasing value. PRACTICAL APPLICATIONSThe addition of latt e art to milk-based coffees is an interesting, and somewhat recent, phenomenon. The inclusion of latt e art can help baristas differentiate their product from those of others. The results reported here suggest that the addition of latt e art influences how much people expect, and are willing to pay for milkbased coffees. As such, for the cafe owner thinking about how to increase profits, the experiments reported here suggest that people are willing to pay between 11-13% more for coffee with latt e art than for those without it.

The flavorsome compounds in coffee beans exist in the form of aprotic charge neutral species, as well as a collection of acids and conjugate salts. The dissolution and extraction of these organic molecules is a process dependent on the dissolved mineral content of the water. It is known that different rates and compositions of coffee extraction are achieved through the control of the water "impurities", Na(+), Mg(2+), and Ca(2+), which coordinate to nucleophilic motifs in coffee. Using density functional theory, we quantify the thermodynamic binding energies of five familiar coffee-contained acids, caffeine, and a representative flavor component, eugenol. From this, we provide insight into the mechanism and ideal mineral composition of water for extraction of flavorsome compounds in coffee.