U is for …. Umami. Until 1908, nobody knew about umami. In fact, that’s probably not the right way to put it: people sensed it, but didn’t have a name for it. Auguste Escoffier, the legendary 19th century French chef, had had an inkling of it – but everyone was too busy eating his delicious creations to bother listening to his gastronomic philosophising. It took a Japanese chemist, one Kikunae Ikeda, to identify umami: the fifth taste.
Up until that point, there had been four universally agreed-upon tastes: sweet, sour, salty and bitter. Each of these tastes was either an encourager or a warning sign to pre-historic man. Sweet connoted high-energy carbohydrate and salt meant mineral-rich foods, while sour and bitter meant acid, poison or rotting. But in 1908, as he nursed his bowl of dashi (a Japanese broth made of kelp), Ikeda realised that the taste of it didn’t neatly fit into any of these categories. He hit upon the idea of a fifth taste, and when he analysed kelp in the lab he narrowed it down to some brown crystals which revealed themselves to be glutamate. Roughly translated, ‘umami’ means ‘savoury scrumptiousness.’
Glutamate is also present in other foods: broth is a quintessential example, but it is also found in cured meat, cheese, fermented sauces, mushrooms and even human breast milk. There is also a second component to the umami taste, and that is a group of chemicals called ribonucleotides. When foods containing glutamate are combined with foods containing ribonucleotides, the result, like alchemy, is greater than the sum of its parts: a savoury mouth-explosion. This may go some way to explaining the popularity of umami-rich combinations: spaghetti bolognese (beef, tomatoes, cheese), leek and chicken or peas and ham.
As the other tastes serve an evolutionary purpose, so umami is a signal for protein. It is thought that this is why cooked or cured meat has more umami than raw meat: in its raw state, the amino acids that make umami – and make an aged steak so delicious – have not been released. Furthermore, umami can be tasted at a concentration much lower than salt or sugar – 16 and six times lower, respectively. Umami is thus being used to make food which is low in the other four tastes more palatable: for example, low-fat or low-salt foods such as that served in hospitals.
Umami has a particular quality that generates salivating and coats the tongue, leaving a long-lasting aftertaste. Even writing the words Marmite, stock and nam pla makes my mouth water. It seems the Ancients felt the same way: Romans used fermented fish sauces, while Medieval and Byzantine cuisines favoured fermented barley sauces. The Chinese have used soy sauce since the third century AD.
It was only in the 2000s, though, that scientists finally located the taste receptors on the tongue that recognise umami. Glutamate, with its appetite-stimulating properties, is often used as an added flavouring (MSG) in crisps, ready-meals (particularly Chinese food) and dressings. There is also a ‘Taste No. 5’ puree, sold in Waitrose, that captures the umami tang with a combination of mushrooms, anchovy, olives, tomatoes and parmesan. This pure, deep taste gives depth and earthiness to foods. It’s why soy sauce makes gravy sing, and why mushrooms can taste so meaty. Umami may be called the fifth taste, but it’s number one to me.