MalFet said:Hmm...I'm not sure what you mean by sugar density. Your sugar is in solution, so its density would really be calculated independently of the water under most conditions. Are you talking about viscosity? There's an argument to be made that colder temperatures increases water retention in the grain bed, but that never was my experience. That might have an impact on lautering rates for fly systems, though I still can't see why it would on a batch system like the one the OP is using.
Yooper explains the cost thing, though bottlebomber correctly mentions some degree of savings that would be had, specifically for the heat left in the grain bed. Like often happens in breweries, there's a tradeoff here between energy use and time.
Yeah you are correct I got so caught up in the temperature itself i forgot this thread was about batch Sparging. And yes I meant viscosity of the sugars.