Yeah, even for a newbie question, this seems like I'm ultra-noob - but I wanted to ask just in case.
The Papazian bible tells me to use 1.5 gallons of my water when boiling, then add the other 3-3.5 gallons (I buy a 5 gallon thing of spring water for each batch) when I'm ready to start fermentation.
The first beer I made was from a kit, and the kit instructed me to use all 5 gallons in the wort. Obviously the advantage of doing it the book's way is that it takes less time to cool down (I also use a copper wort chiller but it still takes a while). Also would take less time to bring to a boil, I imagine.
My question is, is there any DISadvantage to boiling 1.5 gallons and adding the 3.5 gallons of cold water to the fermenter before I add my wort? Or have I just been wasting many valuable minutes of heating/chilling time by using all the water in the wort?