I never heard of freezing juices... I have heard of putting them in the fridge.  I just keep mine at room temp.  I usually go though my batch that I make (about 300ml in about 3 months or less) and no drop in taste.  I have accidently left mine in a hot car once with dirrect sunlight and that was discusting and I 
threw it away because everything just tasted wrong.  I dont think room temperature is bad of it but anything in excess will ruin the product.