Bill Gates has thrown his weight – and his money – behind a Californian startup that believes it can make a rich, fatty spread akin to butter, using just carbon dioxide and hydrogen. And 'butter' is just the start, with milk, ice-cream, cheese, meat and tropical oils also in development.The San Jose company, Savor, uses a thermochemical process to create its animal-like fat, which is free of the environmental footprint of both the dairy industry and plant-based alternatives."They started with th...