Temp of batch sparge water?

(oops, sorry for originally posting this as a reply to another thread, apparently I don't know how the interweb works either! )

Sorry for the noob question but I'm an AG virgin and will be busting my cherry this weekend.

Something that I'm not understanding is why do we RAISE the temp during sparging? I'm going to be doing a batch sparge but after my first runnings, why not just add 154-ish degree sparge water? This is the temp the sugars were created by, so why isn't this good enough to sparge by?

What is the magic of 170 or 180 degree water?

The hotter it gets the more fluid the sugars become. Would you rather wash dishes with cold or hot water?

Hotter sparge water does two things

1. Denatures the enzymes. This stops conversion. If your sparge takes a long time, your beer won't end up bone dry. This is more of a concern to fly spargers.

2. Warmer water makes it easier to rinse the sugar from the grains. Liken this to trying to dissolve a tablespoon of water in lukewarm water versus very hot water.

I don't know man, water dissolves in water pretty easy ;-) I guess you meant sugar?

Good analogy, Bobby.

Moreover, most batch spargers are essentially mashing out when they add their first batch sparge. This will denature the enzymes at work, and thus conversion will stop. Most don't worry about it since they bring to a boil right away, but hey, thought I'd throw it out there.