In many rich countries, food overabundance leads to vast quantities of still edible food ending up in the trash. Bread and pastries are among the most frequently thrown away. You can read about the reasons for this in this article:
Why is so much bread thrown away?
But what happens to all the bread and baked goods that aren’t sold, you’ll learn in today’s post.
So: where does unsold bread go?
One way for many bakeries and supermarkets to do this is to give the surplus goods to third parties such as nonprofit organizations. However, the challenges here are, on the one hand, the legal framework conditions that must be complied with and are also associated with a large time investment and, on the other hand, the responsibility for ensuring food safety that must be borne by the bakeries and supermarkets.
These same challenges often lead many bakeries to use their own “leftover” bread as an ingredient in new recipes. Typically, unsold bread is either dried, mashed, or made into bread syrup.
Leftover bread and pastries are just as often processed into animal feed. Depending on the size of the farm selling the surplus, the buyers are either regional farmers or commercial feed manufacturers. Due to uncertain data, the amount of bread used for animal feed production cannot be accurately calculated.
Another (and the last mentioned here) way to dispose of bread and baked goods that are not sold is to put them in the throwing them in the garbage or having them recycled by Biogas plants to dispose of. “Unlike the sale of surplus bakery products to farmers or commercial feed manufacturers, bakery companies incur costs when recyclers dispose of them for energy, depending on various factors such as the quantities collected or the distance between bakery operations and biogas plants.” 
It can therefore be said that unsold bread and pastries can be used and processed in various ways. However, reused goods often make up only a small portion. The majority ends up in the trash.
What contribution you can make yourself in the household, so that you do not have to throw away your own bread, you can find out in this post:
Ideas for leftover bread
That was: Where does unsold bread go?