Cider
Cider is an ancient beverage. No-one knows when or where it was first made, because the native distribution of its principal component, the apple, is so widespread, from the Near East to Northwestern Europe. In the cider market, ciders can be broken down into two main styles, standard and specialty. The first group consists of modern ciders and heritage ciders. Modern ciders are produced from culinary apples such as Gala. Heritage ciders are produced from heritage, cider specific, crab or wild apples, like Golden Russet. Historically, cider was made from the only resources available to make it, so style wasn't a large factor when considering the production process. Apples were historically confined to the cooler climates of Western Europe and Britain where civilization was slow to develop record keeping. Cider was first made from crab apples, ancestors of the bittersweet and bittersharp apples used by today's English cider makers.
Citric acid
In 1917, American food chemist James Currie discovered certain strains of the mold "Aspergillus niger" could be efficient citric acid producers, and the pharmaceutical company Pfizer began industrial-level production using this technique two years later, followed by Citrique Belge in 1929. 
In this production technique, which is still the major industrial route to citric acid used today, cultures of "A. niger" are fed on a sucrose or glucose-containing medium to produce citric acid. The source of sugar is corn steep liquor, molasses, hydrolyzed corn starch or other inexpensive sugary solutions. After the mold is filtered out of the resulting solution, citric acid is isolated by precipitating it with calcium hydroxide to yield calcium citrate salt, from which citric acid is regenerated by treatment with sulfuric acid, as in the direct extraction from citrus fruit juice.