The science of how salt affects the taste of food is more complicated than you might think – but it’s vital to understand if you want to improve your skill in the kitchen. Ferran Adrià once declared salt “the only product that changes cuisine”. This is because, as he and all seasoned cooks know, sodium chloride not only adds saltiness, which human beings innately adore (because we need it to live), but it also skews the overall flavour to positive effect…Paul Breslin of Rutgers University, who is pretty much the don when it comes to tasting science, gives the example of a grapefruit. Remember, the sweet and bitter notes will already be suppressing each other. “When I add salt to it,” he says, “I then suppress some of the negative notes, like the bitter taste.” By knocking the bitter down, the sweetness – “or other pleasant tastes, such as savoury,” he adds – are released from their bitter shackles.