National Milk Chocolate Day takes place on July 28, 2017. Milk chocolate" is a sweet solid chocolate made with milk in the form of milk powder, liquid milk, or condensed milk added. The U.S. Government requires a 10% concentration of chocolate liquor. EU regulations specify a minimum of 25% cocoa solids. However, an agreement was reached in 2000 that allowed what by exception from these regulations is called "milk chocolate" in the UK, Ireland, and Malta, containing only 20% cocoa solids, to be traded as "family milk chocolate" elsewhere in the European Union.
In the 1870s, Swiss confectioner Daniel Peter had developed solid milk chocolate using condensed milk, but German company Jordan & Timaeus in Dresden, Saxony invented milk chocolate already in 1839; hitherto it had only been available as a drink.Rodolphe Lindt invented the process called conching, which involves heating and grinding the chocolate solids very finely to ensure that the liquid is evenly blended. This enabled Milton Hershey to make chocolate even more popular by mass-producing affordable chocolate bars.
"Hershey process" milk chocolate is popular in North America. It was invented by Milton S. Hershey, founder of The Hershey Company, and can be produced more cheaply than other processes since it is less sensitive to the freshness of the milk. The process is a trade secret, but experts speculate that the milk is partially lipolyzed, producing butyric acid, which stabilizes the milk from further fermentation. This compound gives the product a particular sour, "tangy" taste, to which the American public has become accustomed, to the point that other manufacturers now simply add butyric acid to their milk chocolates. (With material from: Wikipedia)