A spoonful of sugar for your coffee

Abstract

Although we brew coffee and tea in water, the psychoactive drug we crave, caffeine, is moderately hydrophobic and becomes more so as the temperature of a beverage decreases. Stacked aggregates of caffeine molecules, which may have different properties, can form at saturation. Shumilin et al. investigated the distribution of caffeine aggregates and monomers in response to increasing concentration of a common excipient: sugar. Although various sugars decreased overall caffeine solubility, they had a preferential effect on oligomers and resulted in a higher relative proportion of caffeine in the monomer form.