If I were to ask you how many basic tastes there are, I would guess the vast majority of you would answer four. Bitterness, sourness, saltiness, and sweetness. And you would be wrong, as there is a fifth taste called umami. The man credited with its discovery was Kikunae Ikeda, a chemistry professor working at the Imperial University of Tokyo. He was able to extract and crystallise an amino acid called glutamic acid from the soup. Later research discovered that its carboxylate anion, glutamate, activates specific receptors on the tongue making it, indeed, a new taste. Ikeda, realising the potential of this compound as a flavour enhancer, patented a method of mass-producing the glutamate sodium salt, monosodium glutamate (MSG). This salt has the added benefit of dissolving faster than the pure amino acid and has been used in cooking ever since but is it safe?