Both hot and cold break are proteins of different types. The amount of break material(protein) possible in a recipe is dependent on the recipe. While a certain amount is good for head retention, overdoing it does have its own set of problems. Unclear beer, a head that wont drop even in an oily glass(no I have never drank from an oily glass). Normally with a good hot and cold break beer comes out clear with good head retention and lacing without forcing you to suck foam all the way down.