In the late 1930s, children in three Malawian villages were subjected to a peculiar test for vitamin A deficiency devised by Dr. Benjamin Platt, director of the Nyasaland Nutrition Survey and a leading colonial nutrition scientist. Platt constructed a makeshift adaptometer, appropriate for field conditions, that could be placed over a subject’s head to measure retinal adaptation to light. He built this contraption from simple materials, including a five-pound tea-box and sticking plaster. This article takes the curious commingling of commodity objects and scientific materials (where a discarded tea-box finds new life as an experimental technology) as an entry point for examining how scientific practices are woven from semiotic and material threads, demonstrating how heterogeneous social and material elements overlap and influence one another. The article first analyses how Platt’s tea-box adaptometer – and the discourses and ambitions framing the Survey – imagined a new kind of nutrition research hinged to the space of the field rather than the laboratory. It then proceeds to consider how the tea-box, an incipient manifestation of ‘appropriate technology’, points us towards the more tacit ways that tea wove itself into the fabric of the Survey and colonial society, as a gustatory discourse steeped in racial anxieties. Attending to the ‘stuff’ of scientific work cued me to broader imperial circuits and interests that shaped colonial nutrition research.