Through a porthole in a metal tank, I could see a yellow froth churning. It's a primordial soup of bacteria, taken from the soil and multiplied in the laboratory, using hydrogen extracted from water as its energy source. When the froth was siphoned through a tangle of pipes and squirted on to heated rollers, it turned into a rich yellow flour. This flour is not yet licensed for sale. But the scientists, working for a company called Solar Foods, were allowed to give me some while filming our documentary Apocalypse Cow. Such flours are likely soon to become the feedstock for almost everything. In their raw state, they can replace the fillers now used in thousands of food products. When the bacteria are modified they will create the specific proteins needed for lab-grown meat, milk and eggs. The carbohydrates that remain when proteins and fats have been extracted could replace everything from pasta flour to potato crisps. Research by the thinktank RethinkX suggests that proteins from precision fermentation will be around 10 times cheaper than animal protein by 2035. The result, it says, will be the near-complete collapse of the livestock industry. The new food economy will "replace an extravagantly inefficient system that requires enormous quantities of inputs and produces huge amounts of waste with one that is precise, targeted, and tractable". Using tiny areas of land, with a massively reduced requirement for water and nutrients, it "presents the greatest opportunity for environmental restoration in human history".