It is a quirk of technology that occasionally, instead of advancing as usual, it gets stuck at a certain stage. The QWERTY keyboard is the best example, a layout of letters that made sense for a long forgotten typewriter design, but which has persisted because too many keyboard users are too used to it to change.Something similar seems to have affected Indian butter, because it's hard to explain why else it tastes the way it does. It is so strongly flavoured and salty that it can be distinct shock to those unused to it.It is certainly tasty, but it is nothing like the best farmhouse butters of France or Ireland which combine the rich mouthfeel of butterfat with an underlying fresh creamy milkiness and subtle grassy notes from the pastures where the cows have eaten. “Coagulated sunlight,” the Irish poet Seamus Heaney describes it, “heaped up like gilded gravel in the bowl.” Harold McGee, the food scientist, notes that these lines are an accurate description of what happens: sunlight makes grass; cows eat it and convert it into fat that is dispersed as microscopic globules in their milk; after milking, these globules are firstly gently separated out as cream, and then less gently churned to smash them together into the large masses of fat that is butter.The process has long been known in India. Navaneetha is the Sanskrit name for the freshly churned butter which infant Krishna used to steal. Yet problems of storage in a hot climate meant that butter was rarely kept this way. Even after churning butter contains water and milk solids which can turn it rancid, unless it is clarified, by heating it to boil away the water and precipitate the solids.This leaves ghee which is almost pure butterfat and has a long storage life, and this is why, barring Krishna’s pilfering, fresh butter itself was historically little used in India, until the British arrived. Coming from a country where melted butter was often the only sauce used they had to have it, and Achaya notes a reference to butter at an afternoon meal made by a Mrs Eliza Fay in Calcutta in 1780. Perhaps a few dairies were making it in Calcutta, or it was made domestically from the ‘top of milk’ malai saved from the milk consumed at homeBut large scale butter manufacture in India came about thanks to the army and Bombay. The army felt its battalions needed butter and set up Military Dairy Farms across India, whose surplus butter was sold to civilians. Meanwhile farmers in the Kaira district of what is now Gujarat realised that the growth of the railways meant they could supply milk products to the fast growing city of Bombay.A few entrepreneurs, then the government as well, set up dairy operations in the area that made and sent butter to Bombay, but the real growth was to come from a dynamic young Parsi named Pestonji Edulji Dalal who in 1888, aged just 13, started a small shop to roast and grind coffee. According to Ruth Heredia’s The Amul India Story, Dalal’s nickname was Polly, which he adapted into the British sounding Polson’s for this brand name.Polson’s coffee soon got regular customers among the British and by 1910 Pestonji was well established and looking for new opportunities. So when a customer in the Supply Corps told him of the problems the army still had getting butter, he decided to jump in. Pestonji set up a dairy in Kaira and used his army and railways contacts to ensure that Polson’s was so widely supplied that it became synonymous with butter.By 1930 Polson’s had opened the most advanced dairy plant in India and dominated the butter business. But as Heredia’s book points out, it was this dominance that caused Polson’s downfall, since it provoked a Gandhian called Tribhuvandas Patel to organise the co-operative that would ultimately become Amul.It was Patel who persuaded a young dairy engineer called Verghese Kurien to join Amul, and the story of how Amul butter got its taste is given in Kurien’s autobiography I Too Had a Dream. “Polson always made butter from stale cream,” Kurien recalls. “Sometimes these cans of cream would be kept for as long as ten days without refrigeration.” Polson’s weren’t bothered since they had found a way to remove bad odours in the manufacturing process, but Amul was determined to make their butter only of fresh cream – milk to cream to butter, all in the same day.” Yet in the market it bombed, because people felt it tasted flat and flavourless. Kurien discovered that the sour cream Polson’s used, and their heavy salting of the butter to help preserve it further, had given it a distinctive taste to which customers were too accustomed to change.Amul had to come up with a solution and found it in a chemical additive called diacetyl that gave it the required butter taste. (In fairness to Polson’s, it should be noted that its common in Europe to let cream sour a bit so that lactic acid bacteria naturally create chemicals, including diacetyl, to give it a rounded butter taste).They also had to increase salt and add colouring to give their white buffalo milk butter the yellowish colour of cow's butter that people were used to. Kurien wasn’t happy with this, but recognised that some concessions were needed for consumers. Amul’s butter was soon doing better than Polson’s, and ultimately the co-operative would finish off the company. But since we are used to Amul now as we were to Polson’s then, that tangy and salty taste remains with us, long after the company that created it has gone.Amul does have competitors now though, both domestically made and imported, and it is interesting to see how it compares. I found three readily available in the Mumbai market, from Mother Dairy and Britannia (but both produced by Schreiber Dynamix Dairies in Baramati) and Lurpak imported Danish butter.The Lurpak is a good mass market European butter, nothing special, but pleasantly creamy and low in salt – according to their pack details, 470 mg sodium per 100 gm butter compared to Amul’s 836 mg. Since most of us are used to eating less salt these days, Lurpak’s taste is a real relief and somewhat mitigates the fact that it is almost four times the cost of Amul.The Mother Dairy and Britannia butters though seem to be trying to out-Amul Amul: they are really strongly flavoured and saltier, though wisely perhaps, they leave out the details from their packs. Mother Dairy’s flavour attacks you instantly and harshly; this is not a butter I am going to buy again. Britannia’s is more delayed, but leaves acrid after-tastes.Perhaps it is just my conditioning, but Amul does fare best, the most balanced between Indian and foreign tastes. But Lurpak’s low salt is alluring and perhaps Amul should consider a version, especially since the growth of cold chains and supermarkets means that storage is no longer such an issue. It would surely be ironic if after these years all the old Parsi could yet have some revenge by seeing some Amul customers driven to foreign brands by the persistence of the Polson’s taste.