All your life, you've been lied to. Turns out they're not bloody baked beans, they're stewed beans. They don't do what they say on the tin. Someone needs to take Heinz and the supermarkets and the rest of the mislabellers to the ASA. Someone needs to spill the beans.

The beans in "baked" beans are navy beans, common beans, Phaseolus vulgaris, the same and vital species that gives us kidney, cannellini, french, black, pinto, haricot, flageolet, borlotti and marrow. They are native to the New World and, along with squash and maize, formed the so-called "three sisters" that were the agricultural base of Native American cultures. Such beans contain up to three times the protein of rice or wheat, making rice and beans, stalwart dish of the Americas and the Caribbean, almost a complete meal.



A number of indigenous American tribes seem to have baked their beans with bear fat, venison and maple syrup, covering earthenware pots with hot stones and teaching this technique to the arriving Europeans. The pilgrims were forbidden from cooking on the sabbath, so a Saturday supper of baked beans could be kept warm as a stout and godfearing breakfast for the next day. In New England, baked beans evolved into a dish of stewed beans (you see where we're heading) cooked with salt pork, molasses and spices, though recipes still referred to baked beans. Massachusetts proclaimed the navy bean its state vegetable in 1993, and Boston is still occasionally known as "Beantown".

It was these "baked" beans, stewed with pork and molasses, which were first tinned – or canned in American parlance – around the US civil war in the 1860s. (More than one cannery claims to have been the first to do so.) Tinned beans had the happy fortune of succeeding the first tin opener, patented in England in 1855: before that, opening tins involved hammers and chisels and blood and swearing. Heinz Baked Beans arrived in Fortnum's in 1886 as an exotic luxury; the American company only dropped the pork from the product during second world war rationing.

It's difficult to overstate the success of Heinz Baked Beans in the UK. The company has a market share of almost 70%, and claims that, every day, 2.3m Brits eat its beans from around 1m cans. Heinz's export recipe gradually evolved into a less sweet version with more tomatoes, since aped by all of its competitors. I was reared on Heinz ketchup and I find nothing else matches that sweet-sour bloodiness, but the beans are a different story. In blind tastings Heinz invariably comes near the bottom: last year the consumer advice group Which? placed them fourth equal after Branston, Asda and Morrison's. At one company's in-house tasting earlier this month Tesco won, followed by Branston, with Heinz coming last out of six brands sampled. Once again, devotion to a specific brand has more to do with history and memory than taste. Beans no longer mean Heinz in my house: I buy Branston (no interests), which are less mushy and have a much richer tomatoey savouriness.

A wee note on farting. Beans are rich in sugars called polysaccharides which humans can't digest. When the sugars reach the lower intestine the resident bacteria feed on them and produce gas. In 2006, Venezuelan scientists announced the first "fart-free bean", in which black beans were fermented with a specific bacterium to break down the polysaccharides before eating. According to the BBC you can also reduce this effect by "blasting [beans] with radioactive waves", but alas you'll need a licence to do so in Europe.

Baked beans may be an essential addition to a fry-up, though Guardian reader favourite AA Gill calls them "de trop" in The Wolseley's breakfast book. They're apparently obligatory in the vegetarian version of the Full English, whatever that is. Boston baked beans is a lovely winter supper: Andy Appleton, head chef at Fifteen in Cornwall, sent me a nice recipe for creamy borlotti beans which I've been whacking on toast for breakfast. Our Hugh also has a good method for Boston baked beans. How do you like your stewed beans?