In the early 20th century, Americans were highly concerned with the purity of their food supply. In the case of bread, hand-kneading was suddenly seen as a possible source of contamination... Mass-produced bread, on the other hand, seemed safe. It was made in shining factories, mechanically mixed, government regulated. It was individually wrapped...
But factory breads were also incredibly soft... “Softness,” Borrow-Strain writes, “had become customers’ proxy for freshness, and savvy bakery scientists turned their minds to engineering even more squeezable loaves. As a result of the drive toward softer bread, industry observers noted that modern loaves had become almost impossible to slice neatly at home.” The solution had to be mechanical slicing.
Factory-sliced bread was born on July 6, 1928 at Missouri’s Chillicothe Baking Company. While retailers would slice bread at the point of sale, the idea of pre-sliced bread was a novelty... The bakery saw a 2,000 percent increase in sales, and mechanical slicing quickly swept the nation.
14 June 2012
Why Americans eat sliced bread
An explanation from the Smithsonian's Food and Think blog: