H to the no. If you are using frozen blueberries, do NOT thaw them first or macerate them! When you put berries in the freezer, the cells start to expand as they freeze, and the high water content of the berries can actually cause the cells to burst. The softening of the blueberry skins (that we are trying to achieve with the macerating step) is already done, and then some! A pie made with frozen berries will look a lot juicier when you take it out of the oven, but if you wait the appropriate amount of time before slicing into it, it will have roughly the same texture as this pie made with fresh berries.