Decoction mash with batch sparge - volume additions query
I want to make a Weizenbok and wanted to try using a single decoction mash followed by a batch sparge. I've been using Beersmith for all my single infusion / batch sparge recipes so far and have found it to be spot on with vols and temps, SG readings.
I was a bit unsure for the amount of batch sparge water BS says to add when doing a single decoction mash for 18 lbs of grain with a batch size of 6 Gallons.
The settings/figures in the mash profile are currently:
Protein rest: add 9.41 US Gallons of water at 127F; step temp 122F; step time 35mins
Saccharification: decoct 3.86 US Gals mash and boil it; step temp 154F; step time 45 mins
Batch sparge with 1.42 US gals of 168F water
(this doesnt seem like a lot of water (proportionwise)..... when I do infusion mashing, I would normally add 5.92 gals water (mash in); then add approx 2.38 gals batch sparge 1st step;steep; drain the lot into the boiler; add another approx 2.38 gals sparge water 2nd step);steep; drain into boiler.)
Am I right in thinking that I dont have to do a mash-out as I'm batch sparging with lage vols of liquor?
Anyone out there throw some light on this please?