The announcement in March that Marmite, Britain's most popular savoury bread-covering, is to be sold in clear plastic tubes instead of brown jars was met with wails of nostalgic anguish. A Save our Marmite Jar campaign was mooted—until it emerged that the tubes will still, for now, sit on supermarket shelves beside the pot-bellied jars.
Unilever, which acquired the brand six years ago, says it is "delighted" with the Marmite relaunch. It is the latest success in a campaign to establish "My mate Marmite" as a condiment that runs in veins near the very heart of Britishness itself. Sales are rising—up to 14m jars, £27.5m worth, last year. How much Unilever will save by using plastic instead of the old peat-brown glass, or indeed by thinning the solution of Marmite so it flows more freely, the company won't say. They are oddly shy about Marmite—both about what it is and what it costs to make.
It doesn't cost much. The processed food business excels at putting near-worthless substances into packets and selling them at a premium: Marmite may be one of the most remarkably marked-up items of all. It is a waste product of industrial brewing, a sludge left from the fermentation of yeast and sugars, stabilised by the addition of salt. Marmite's first factory was established in 1902 near the Bass brewery in Burton-on-Trent; it was true once, if not now, that the brewers paid Marmite's makers to cart the stuff away.
The other thing that Unilever doesn't tell you is what Marmite is. On the pot it lists a few flavourings and vitamins, as well as "yeast extract." The latter is one of the many euphemisms tolerated by food labelling authorities across the world for monosodium glutamate: MSG, the Agent Orange of food additives. It is blamed, by nutritionists and parental support groups, for a range of ills starting with the headaches and palpitations people believe they get from Chinese food through to childhood asthma and attention deficit disorder. Marmite has 1750mg of monosodium glutamate in every 100g: more MSG than any other substance in the average British larder (a well-matured parmesan cheese might come a close second).
No wonder Unilever doesn't put MSG on the label. And it wriggles away from the subject under questioning. "There's no MSG in Marmite," says Unilever's customer care line. Pressed, this becomes "no added MSG"—and then you're assured that the MSG that is present is "naturally occurring." Quite how natural you can call an industrial process that breaks down yeast proteins by heat and centrifuge into amino acids is something customer care won't debate. You might as well call carbon a naturally occurring substance in petrol.
MSG is what makes Marmite work, of course. It's a simple substance, a salt of glutamic acid which is present in many foodstuffs including mothers' milk. Glutamate makes things more tasty by stimulating nerve receptors in the taste buds: the reason it's present in breast milk, it is thought, is that, along with the sugar lactose, it encourages babies to eat more. The same thing happens when we put other MSG sources—strong cheese, cured meat, cooked tomatoes or soy sauce—on a plate of bland carbohydrates: we stimulate our appetite. Glutamate and its analogues appear to work on quite separate receptors from those excited by other chemicals, and neuroscientists have recently decided that the taste is a unique, fundamental one, inadequately called "savoury" or "tangy." The Japanese scientist who first isolated glutamate in stock made from dried seaweed 100 years ago gave it a rather more poetic name: umami, or deliciousness. It takes a place alongside sweet, bitter, salty and sour in the basic palette that our tongues can detect. It is a fifth taste.
Without MSG, Marmite would not work, and the processed and packaged food industry would not exist as we know it. MSG found its way from Japan to America after the second world war. The arrival was timely—as canned and frozen food took off, a key problem emerged. When you subject foods to necessary heat or cold to pasteurise them, they lose taste. MSG replaces it, though usually coyly billed as "hydrolysed vegetable protein" or by the E numbers 620-625, which signify a range of related glutamates. The world consumes 1.5m tonnes of it a year.
So how bad for you is MSG? Fear of MSG began with a 1968 New England Journal of Medicine paper identifying "Chinese restaurant syndrome." Studies followed showing that mice injected with vast amounts of MSG developed brain lesions. A panic was born. MSG has since been "linked to"—that fatal pop science phrase—anything from asthma to Alzheimer's.
But none of the scores of studies carried out on humans has ever shown conclusively that it does any harm at all, even in unrealistic doses. Rather the opposite: by reducing the need for salt in food, it may do some good. Every government body that pronounces on these things has long ago put MSG on its list of safe food additives; the industry responded by finding a nicer name for it. But nearly 40 years on, the myth persists: polls of parents in the west find that over 70 per cent still believe MSG is harmful and would not let their children consume it (good luck to them). Asians, of course, are immune to such concerns: in Thailand and China a little bottle of MSG appears beside the salt, sugar and the crushed chilli on restaurant tables.
Deliciousness is clearly all around us, but if you want to experiment, MSG can be found in Chinese supermarkets in pure form in tins marked "gourmet powder." A little mixed into an omelette gives an idea of what it can do—and if you get pains and flushes later, you may attribute them to mass hysteria. Alternatively, there's Marmite—a half-teaspoonful will cheer up the dimmest stock. And whoever got a headache from eating Marmite?
