60min. boil?

[Allsup]

What's the point of the 60min boil in AG or partial mash brewing? Is it only for the hops bittering or also to denature the proteins and other chemistry words?
What would happen if a person only boiled for 30min or only boiled 50% of the volume. Adding fresh water at the end to reach a final volume of 5 gal.? I'm a rookie just starting to look at AG brewing. Thanks for the help.

 

[GilaMinumBeer]

For hop isomerization, protein coagulation, and, depending on the malt, SMM to DMS conversion.

 

[dschof]

I brewed a Dale's Pale Ale clone and learned not to measure the wort during the boil. I extended the boil for 20 minutes in order to get my projected wort for the fermenter and I ended up being way short (about 3/4 gallon). Grrrr. Hot liquid takes up more space than cool. I learned to make a plan and stick to it. Plus, I learned to put pellet hops in a fine mesh bag. They clogged my system up like crazy which caused my day to be longer, more frustrating plus I lost more wort in the process. Brew and learn every time...

 

[MikeG]

After mashing my grains I'll collect a low gravity wort (same for all AG brewers). The boil is not only for hop utilization it's also to boil off some of the water volume so I end up with the correct volume and gravity of wort before pitching.