How should Nutella be stored?
Unopened and opened jars of Nutella should be stored at room temperature.
Keep the jar tightly closed and store in a cool place to maintain maximum flavor.
Do not refrigerate Nutella or it will be difficult to spread. Excessive heat will
accelerate the loss of fresh flavor and may cause the oils found in Nutella
One more thing you should take care about that always go to the manufacturer's website to find out such informations as they only know the constituents of their products and their basic infos.
I have sourced the above info. from the manufacturer's website which is as below:
You will get tonnes of more info about this product on above website.