Why do manufacturers tell you to refrigerate many things that don't require it?!
Answers: I have seen "refrigerate after opening" on things that a person would never stick in the fridge because there is no reason to. There are foods that do require refrigeration to prevent food poisoning but this warning label is on practially everything now.
To cover themselves legally. If it went bad and you got sick, you could sue them.
After opening some things, you loose the air tight seal, therefore it can go bad.:)
Because we live in a law suit happy world ;)
What things are you talking about? Most things that I put in the refrigerator needs to be put there.
Legally on some products they may be required but I think the real reason is for preservation. When you open something it is in an air tight container and the more it sits out it is going to lose it's flavor. Close to anything can lose flavor on openening.
I look at it in this way, if you open thier product but don't actually use it and dont refrigerate it then go back to use it later and it does not taste how it should, then you probably won't buy that product again, or at least from that company.
.....and why does 'sour cream' have a use by date?
One reason is to make non-perishable goods seem "fresh", and thus more expensive. Eg, a box of chocolates that contains fresh cream is very expensive. A cheap box of chocolates can be made to seem expensive if you print "keep refrigerated" on the box. Some manufacturers even sell "cheap" chocolates from a special fridge in the supermarket, to make you think you're getting top-quality produce when actually you're getting the standard stuff.
it is safer for you and therefor safer for them.