Previous studies suggest that glassware design may influence drinking behaviour, however it remains unclear whether these effects are limited to alcohol, and what the underlying mechanisms are. This study investigated the effect of glass shape on total drinking time for a soft drink, using inward-sloped, straight-sided, and outward-sloped tumblers. We explored two sets of underlying mechanisms: micro-drinking behaviours (e.g. sip size), and perceptual effects (e.g. volume judgments).

Drinking was ~20% faster from outward-sloped glasses than straight-sided ones. This extends previous research, suggesting glass shape may influence drinking speed for a soft drink. Though glass shape influences ability to judge volume (perceptual effects), we found no evidence that this related to drinking speed. Changes in the micro-structure of drinking (e.g. sip size) may be important in driving the effect of glass shape on drinking speed, and future studies, powered to test these mechanisms, are warranted.

Impact of glass shape on time taken to drink a soft drink: A laboratory-based experiment. Langfield T, Pechey R, Pilling M, Marteau TM. PLOS ONE, 2018.
Access full text.