jtoots said:
looking to learn from this tidbit... why do you want to sparge with water hotter than 170, which i read can release tannins?
I don't...but just like your initial infusion water temp is usually hotter then 170 to hit your 156 or 158 mash temp target..so must be your sparge water temp to hit your 165 target for mash out / sparge process. Your going to loose those extra degrees instantly trying to raise the mass already in the mash tun that's at a lower temperature.
Just like the initial grains and your room or outside temperature mash tun will suck heat from the infusion water , so does the mash that's already there before sparging because its at a lower temperature. BeerSmith calulates this initial infusion water temp for you but not your sparge water temp and It just as easily could/should.
Its more critical for those of us that use coolers and do not constantly heat each vessel as the progress progresses down the line. Our Goal Should be to have 165 degree ( or close) wort draining from our mash tun's not just entering it.
For example......For 10 pounds of grain already in the tun sitting at 158f is roughly going to translate into a almost "instant" loss of 9 degrees of your sparge water temp by adding your 1 batch sparge of say 4+ gal of water into your mash tun all at once. this temp loss will even be a worse loss curve when fly sparging as your asking a small trickle of water to raise a large mass at a much lower temp. I think you will find your efficiency will increase a few percentages, as you will actually be washing/extracting sugar's at the proper ideal temp. And not an over temp extracting off flavors due to the almost instant drop in sparge water temperature.
I went to an All Grain Class at my LHBS and they had some sort of a equation to figure this out but to be honest the instructor just said he knew what it should approximately be just from experience. This temperature will change with mash volumes though, so to me its just better to have a program that figures it out for us . BeerSmith could be one of the best platform's for this. Right now I'm using a different program to figure it out for me.
Here is an example from the other program that I labeled as" Winter" , which has my outside Mash tun temp and grains already calculated into it for a 50 degree day:
Infusion - Winter : Add 3.281 gal water at 173.530 F to mash to bring it to 158.000 F. Hold for 60.000 min.
Infusion - Final Batch Sparge : Add 4.606 gal water at 177.692 F to mash to bring it to 165.200 F. Hold for 15.000 min.