A shot of pallets loaded with loafs of bread in a distribution warehouse.
The Reason Store-Bought Sandwich Loaves Last
So Long
By Elias Nash
Anyone who has ever made bread or bought it at a bakery knows how quickly it usually goes stale. Of course, the bread you buy at the grocery store is going to last a lot longer, thanks to the preservatives that are added to it.
The most prominent preservatives added to commercial bread are enzymes, which make the dough hold more gas, creating lighter and longer-lasting bread. These include diastase (amylase) — which helps the dough expand and aids in browning the crust — and protease — which softens the gluten, making the dough elastic.
Another group of preservatives often added to bread is antimicrobials, which prevent mold from growing on the bread. While some of these are natural, synthetic ones are often added as well, so if you’re wary of chemical additives, it's best to avoid those pillowy loaves of sandwich bread.