If you were to point to the most marvelous product kicking around in your pantry right now, would it be your loaf of bread? It is one of the most mundane staple foods, but as Aaron Bobrow-Strain shows in his book White Bread: A Social History of the Store-Bought Loaf, the lowly loaf is so much more than the sum of its simple parts. In American culture, bread is a status symbol, and the book provides a fascinating look at how store-bought white bread rose and fell in prominence. The book also answers the big question: Why do we have pre-sliced bread, and why it was the greatest thing to hit grocery store shelves?

To understand sliced bread, one must first understand the dramatic shift in bread making habits in America. In 1890, about 90 percent of bread was baked at home, but by 1930, factories usurped the home baker. Considering that bread making had been a part of domestic life for millennia, this is a fairly rapid change. 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, and yeast—those mystical, microscopic organisms that causes dough to rise—were viewed with suspicion. “Bread rises when infected with the yeast germ because millions of these little worms have been born and have died,” Eugene Christian wrote in his 1904 book Raw Foods and How to Use Them. “And from their dead and decaying bodies there rises a gas just as it does from the dead body of a hog of any other animal.” Images like this hardly make someone want to do business with the local baker.

Mass-produced bread, on the other hand, seemed safe. It was made in shining factories, mechanically mixed, government regulated. It was individually wrapped. It was a product of modern science that left nothing to chance. It was also convenient, sparing women hours in the kitchen to prepare a daily staple. Factory loaves also had an attractive, streamlined aesthetic, dispensing with the “unsightly” irregularities of homemade bread. Americans fed on factory bread because the bread companies were able to feed on consumer fear.

But factory breads were also incredibly soft. Buying pre-wrapped bread, consumers were forced to evaluate a product under sensory deprivation—it’s next to impossible to effectively see, touch and smell bread through a wrapper. “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 housewife can well experience a thrill of pleasure when she first sees a loaf of this bread with each slice the exact counterpart of its fellows,” a reporter said of the sliced bread. “So neat and precise are the slices, and so definitely better than anyone could possibly slice by hand with a bread knife that one realizes instantly that here is a refinement that will receive a hearty and permanent welcome.” The bakery saw a 2,000 percent increase in sales, and mechanical slicing quickly swept the nation. With Americans all agog at the wonders of the mechanical age, sliced bread was a beacon of the amazing things the future might hold. At least that was the mindset. “Technology,” Bobrow-Strain says, “would usher in good society by conquering and taming the fickle nature of food provisioning.”