[masraum]

Originally Posted by wdfifteen

You WANT the ice to melt. Melting of ice is an endothermic reaction, ie it absorbs heat. The heat it absorbs is from the beer or whatever in the cooler.

Assuming you've got warm stuff that you're trying to get cold. But, if that's the case, you also want as much ice as possible because the phase change will absorb the most heat while retaining the lowest temp. If you had 10# of water at 32.1º and dropped a bunch of warm beer in it, you may not cool the beer to your satisfaction. If you put the beer in, and then as much ice as you could fit, and then some water (such that ice and water = 10#), the melting ice would rapidly cool the beer and you'd still have a bunch of ice to keep the water and beer cold.

THe more ice the merrier. Water to fill in the gaps without displacing ice (assuming you'd adding cold water. You don't want to add too much warm water or it'll cause the ice to melt. You want the heat from the beer to melt the ice, not heat from the water.