For centuries, the term "from scratch" has meant "from the beginning" in everyday English. Originally, it referred to the starting line in a race, which was often simply a line, or a "scratch" drawn in the dirt. This is also the source of the expression "up to scratch," which refers to the line a boxer had to stand on at the beginning of a round. By the early 20th century, the general meaning of "from the beginning" or "without extra help" developed into the more specific cooking sense of "from nothing."

The most common use of "from scratch" in baking is to refer to baking without using packaged ingredients such as cake mixes, pie crusts, cookie dough or frosting. But how little preparation is permissible? Cooks of previous generations sometimes bred their own yeast or ground their own flour. Astronomer Carl Sagan famously said that "if you wish to make an apple pie from scratch, you must first invent the universe," pointing out that even basic ingredients come from somewhere else. The exact definition of "from scratch" can vary from person to person.

Baking from scratch has a number of advantages over using store-bought goods. For many, home-baked bread, cakes and treats have a quality that you cannot equal by a mass-produced baked good. Additionally, baking from scratch enables the baker to customize, adjusting the recipe to suit his tastes. Baking from scratch can also be cheaper than buying baked goods at a store, although this isn't true for all products.

When food writer Jennifer Reese compared the costs of cooking from scratch and shopping for staples, she intentionally omitted the time spent cooking from her calculations. This makes sense for those for whom baking is a hobby; the time they spend cooking is part of the enjoyment they receive. For those with busy schedules, however, or for those in which time spent in the kitchen would be more enjoyably spent elsewhere, using prepared ingredients can be a valuable shortcut.