We all know that that the same foods - in this case carrots - can taste very different from each other, and that taste is often a guide to its quality. There is a device for measuring the quality of nutrients in foods, and it's called the Brix Refractometer. It's something that each of us could be using at home if we wanted, in our gardens and allotments. Matthew Adams, from the group Growing Real Food for Nutrition (Grffn) is on a mission to turn us all into citizen scientists and comparing notes on the vegetables we grow. Ultimately this will improve not only the foods we grow, but also the health of our planet.