Mash and Sparge volumes for BIAB?

[mychalg9]

I did some searching but didnt find exactly what I wanted to know. I recently acquired an extra 30 qt pot so I am curious to try a biab with sparge, using the second pot. I've been making 2.5 gallon batches lately just to get my processes down, and have been attempting a "sparge" by just pouring hot water over the grain bag and letting it drain into the mash. So assuming I am making a SMASH recipe with 5 lbs of grain, how much water should I use in my mash and how much in my sparge? Do you just divide the total water in half into each vessel? Does the mash consistency matter in a BIAB? I imagine there is no real wrong way to do it, just wondering if anyone favors one way over another or if there is an easier way or whatever. Thanks for any insight

 

[deepcdan99]

I don't particularly pay too much attention to the water/grain ratio when I do BIAB but you could split it in half if you were to think it would be too thin. I do no sparge full volumn BIAB and have never had any problems. I suppose you just wouldnt want the mash too thick so you get full conversion. Also, a SMASH is a single malt and single hop recipe. Usually done to get good idea on specific characterstics on hops or grains.

 

[djfriesen]

I'm finding mash thickness doesn't matter too much in BIAB. I will typically mash with a volume that is easiest to measure out that comes somewhere close to 1.5 qts/lb of grain. Once I've accounted for grain absorption, I dunk sparge in whatever is left over to get me to pre-boil volume (7 gallons for me). I'm thinking about trying to do a split dunk sparge (i.e. mash thick and split the sparge water into 2 equal volumes and dunk in both) as I have heard this might help bump up efficiency.