To buy juice in cartons or jugs rather than in its frozen form is cost inefficient. You're essential paying for water and a higher price for the privilege of carting that heavier weight home.
The frozen form of juice has changed over the past few years. Now you will find in the frozen juice section three types of product:
- frozen (orange, grapefruit...) juice from concentrate
- frozen concentrated (orange, grapefruit...) juice
Only the third is pure juice.
In all three cases, manufacturers' instructions call for adding three (less often four) cans of water to the frozen goop. Products one and two have water and sugar added.
Be especially wary of the difference between frozen juice from concentrate and frozen concentrated juice. Manufacturers make their packaging of these two products eerily - I submit, intentionally - similar. Only the last one is the real deal and that's the only one you should be buying.
The better, pure product is more pricey, but wait for the sales. Don't be fooled into purchasing the wrong one.