When I was a kid (20 years ago) my parents would make pickles, and some assorted pickled veggies. Usually the veggies would come from a farm around us or an auction where you could buy trays of veggies about the size of a flat of canned drinks. They would also do some fruits in syrup, mainly ones that my uncle would bring us from another part of the country where him and his neighbours had fruit tree.
This is how it happens for most large retailers from what I can gather. You can subtract that from the sales pretty easily though, it would be in the monthly sales reports and we even had a way to figure it out on a daily basis with the comptroller.