Sweet like chocolate

In the July issue of Acta Crystallographica Section C, Nicholls et al. (2019[Nicholls, D., Elleman, C., Shankland, N. & Shankland, K. (2019). Acta Cryst. C75, 904-909.]) report the discovery of a new polymorph of αβ-D-lactose through the oven drying of concentrated aqueous solutions of D-lactose. The authors inter­est in this system was piqued in relation to the properties of chocolate crumb and the process by which the crumb is made. The drying process by which the crumb is produced is a potential mine of inter­esting solid-state transformations and in this case the authors simplified the system from a complex mixture of milk and sucrose to a concentrated aqueous solution of lactose. This simplification of the system has enabled the authors to focus in on the phase transitions that occur in the system and analyse the crystallization products with high-quality crystallographic information. Lucky for Acta Crystallographica Section C that such a delicious structural study was published here