The fact it goes off quicker is the key piece of evidence. Obviously, they sell items in preserves too, they are a supermarket, and walmart will sell fresh items, but aldis main shtick and selection focus is "fresh, good quality and cheap", but stocks vary a lot, so you need to be comfortable with some items not being available sometimes.

For example, I wanted cherry tomatoes last week, but they had none so I had to have piccolo tomatoes instead.