The Shanghai Soup Dumpling Index is a

scientific investigation into the quality of soup dumplings in Shanghai. It applies a quantitative framework to the existing qualitative descriptors of the Shanghai soup dumpling (hereafter also referred to as “xiao long bao”): thin skin, plentiful soup, abundant filling, fresh meat (皮薄 汁多 馅大 肉鲜). A total of 52 restaurants were sampled for this index between December 2013 and October 2014 in Shanghai, People’s Republic of China.

        Four measurements were collected: the weight of the intact dumpling (g); the weight of the soup (g); the weight of the filling (g); and the thickness of the skin (mm). This data was then calculated with the formula [(Filling + Soup / Thickness of Skin) x100] to assign a score representing the quality of structural engineering, the major challenge in the construction of a xiao long bao that meets the colloquial standards.

        An analysis of the results combined with directly observed sensory research found xiao long bao with a score of 12.00 or above to demonstrate successful engineering. From a sensory perspective, these samples showed only minor variations, and were classified as Class A. Xiao long bao below this threshold but above a score of 6.75 showed satisfactory engineering and were judged Class B. A full explanation of the methodology, a quantitative analysis of the effect of time post-steaming on a dumpling, a list of all restaurants sampled (including directional information for all 18 Class A and Class B restaurants) and more is included in the full index, available for sale below.