Does a batch twice the size need twice as much fruit?

[BrewVerymore]

I'm brewing a beer out of a book that calls for 6lbs of raspberries for a 5 Gallon batch. I'm making a 10gallon batch and was wondering if I should just double the amount of fruit or not.

 

[Revvy]

More than likely to get the balance of flavors right. Just like in cooking recipes are scalable.