Wort evaporation question.

[benko]

I'm going to brew a half batch (2.5 gallons) of an experimental brew. Normally, with my setup, I need 6.5 gallons preboil to end up with 5 (1.5 gallons evaporate). My question is, the half batch shouldn't matter on how much evaporates, right? I'm still going to lose 1.5 gallons, vice .75. Meaning I'll need to start with 4 gallons to end up with 2.5. Is my reasoning off? Thanks.

 

[Sixbillionethans]

Seems like solid reasoning. I think boiling evaporation rate is a function of surface area, so if you didn't change your brewpot, it shouldn't change the evaporation rate. There may be some other function there, I suppose.