The Grocer's 150 defining moments: the 1860s

1862… Pasteur pasteurises… A scientific revolution. Until now nobody has really known why food goes off. Over the ages the finger’s been pointed at everything from dirty air to the devil himself. Then Louis Pasteur and Claude Bernard come along and prove that micro-organisms are responsible for the souring of milk, beer and wine.

The two French chemists develop a method of heat treatment to kill off most mould and bacteria present in food stuffs, making them safer to eat or drink for longer. The breakthrough doesn’t just lead to the industrialisation of the dairy industry - it lays the foundations for modern medical thought by establishing the germ disease theory. People live longer, better fed lives as a result.

1862… Rowntree’s out first chocs… Kit Kat, Smarties, Aero… Henry Isaac Rowntree sets up the company that will later be responsible for rolling out many of the nation’s favourite treats. It becomes one of Britain’s biggest companies, before being bought by Nestlé in 1987 for $4.6bn.

1863… Europe develops a coke habit… What do you get if you steep coca leaves in a good Bordeaux? Vin Mariani, a heady brew packing 6mg of pure cocaine per fluid ounce. It’s a hit - the Pope and Queen Victoria soon develop a taste and it inspires Coca-Cola maker John Pemberton.

1863… Co-operatives join forces… The co-operative movement is already well established, but as 300 co-ops team up to form the North of England Co-operative, the first big buying group is established. By 1872 it’s known as the Co-operative Wholesale Society.

1869… Sainsbury sets up shop… It’s not rocket science. Simply offer quality food, good service and high levels of hygiene at competitive prices and they will come. That’s John James Sainsbury’s thinking when he sets up shop with wife Mary Ann on London’s Drury Lane.

His philosophy serves him well. By the time he dies in 1928 - according to legend with the famous last words of “keep the stores well lit” - his empire numbers 128 stores and his record includes a number of firsts for British retail, including the country’s first training school for shop staff. Today the Sainsbury family still holds a stake in the business and the company’s estate stretches across nearly 20 million sq ft and comprises almost 1,000 supermarkets. And old John James can rest easy - all of them are kept well lit.

1869… An icon is born… As canning is commercialised, an icon is born. Joseph A Campbell and Abraham Anderson can everything from tomatoes to minced meats. A century on, Andy Warhol immortalises Campbell’s Condensed Soup with his iconic prints.

1869… Believe it: it’s not butter… Dieters have a lot to thank Hippolyte Mège-Mouriès for - dairy farmers don’t - after the French chemist dreams up oleomargarine (using recently discovered margaric acid). It’s not until 1957 that margarine sales beat butter for the first time, however.