Does slicing bread make it go bad faster?

Yes, slicing bread does make it go stale and go bad faster. This is because slicing exposes more surface area of the bread to air, which accelerates the staling process. When bread is baked, the starch molecules in the dough undergo a process called gelatinization where they absorb water and swell up. As the bread cools, these starch molecules start to recrystallize and firm up again, causing the bread to become stale and hard. Exposure to air speeds up this recrystallization of the starch. An unsliced loaf has just the two end surfaces exposed to air, acting as a protective barrier. But when you slice the loaf, you create many more exposed interior surfaces that allow air to penetrate and cause faster staling. The tips to keep bread fresh longer are:
  1. Don't buy pre-sliced bread from the store. Slice it yourself just before eating.
  2. When slicing a loaf, cut from the middle rather than the end. Then push the two cut halves back together so the intact ends act as a barrier against air exposure.
  3. Store bread at room temperature in a paper bag or breadbox rather than plastic, which traps moisture and encourages mold growth.
So in summary, the more surface area exposed to air by slicing, the faster a loaf of bread will go stale and become inedible.
how to store bread to make it last longer
does freezing bread make it last longer
how to tell if bread has gone bad