I have been figuring the water volumes by inputting a random number for quarts per pound into the brewing software.Then adding up the mash water, and sparge water to get a total amount needed. Take that number and divide by two to get equal amounts for mash and sparge. Then I use a someother software to make sure I can fit the mash water in the tun. If not I adjust it tll it will fit.
But I have been running into the problem of not being able to fit all the sparge water into the mash tun.
Is there a way to figure out the volume of sparge water that will fit after the I drain the first runnings? I know I really just need a bigger mash tun but that isn’t in the cards right now.
Green Bay Rackers--Mash Calculators is the only calculator I know off. For sparge water you will have to add the water absorption in the grain. I don’t think the calculator is perfect. It could be that different grains displace different amounts of water.
That’s what I use to see if my mash will fit.
What I want to know is will my sparge water fit?
I have 8.5 lbs of grain
I mash with 3 gallons of water 1.4 quarts per gallon
this takes up 3.74 gallons in the mash tun.
I then mash out with 1 gallon boiling water.(I know this isn’t really necessary)
And then drain.
I then collect 2.75 gallons of wort.
For 6.5 gallons pre boil I need to add 3.75 gallons of sparge water.
I want to figure out if the 3.75 gallons plus the grain will fit in the mash tun?
The ROT is 0.09 gal per lb of grain. That will vary somewhat depending on kernel size, crush, etc. But it should be a decent starting point. Once you’ve drained your first runnings, it will over-estimate because of the soluble extract you’ve removed, but that just gives you a safety margin. For your example, an 8.5 lb grist, after being drained, would have a volume of 8.5*(0.09 + 0.13) = 1.87 gal, so once you add the 3.75 gal of sparge water the total volume will be ~5.62 gal.
What does the 0.13 represent?
That would be the water absorbed. He’s saying that one pound of grain takes up about 0.09 gallons. One pound of grain will also absorb about 0.13 gallons of liquid. Add the two up and that tells you how many gallons of space your wet grains will take up.
got it thanks
I thought the 0.9 was absorption ratio not the 0.13
so
mashwater+(.09 x lbs of grain )= mash volume ?
Right.
and
preboil volume+(lbs x 0.13)= total mash and sparge water?
Assuming there’s no dead space in the tun, that’s it.
I’d recommend a double batch sparge, regardless of your tun-size situation.
But…What size is your tun?
I use a 10 gallon Rubbermaid & have found large grain bills are not a problem with the DBS.
Mash tun is 5 gallons.
I know I can do the double batch sparge, but I have been getting good efficiancy
with the single, around 80%. Also I like playing around with the #'s and I have have too much free
time.
I too have a 5 gal mash tun and for anything below 14 Plato I tend to be able to get away with a single batch sparge. You only gain about 3% lauter efficiency.
Kai
Do you think you could post some of the mash water, sparge water volumes and grain weights that you know work in the 5 gallon mash tun?
I am trying to see if I have this figured right.
Over on the HBT forum some folks are trying to explain to me how with smaller grain bills they need to double batch sparge and with larger ones they can do a single? This to me is totally counter intuitive. Larger grain bill means more water and more grain taking up room in the mash tun. So how does a larger grain bill lend itself to a single batch sparge?
I never saw a post with " My grain bill is to small to do a batch sparge?"
??? ???
The largest beer I brew is my Doppelbock which takes about 6.5 kg of grain and ~16 l of mash water. This really fills the mash tun to the brim. The key with large beers is to get good efficiency in order to keep the grain weight lower. But the resulting thick mashes don’t necessarily get good efficiency as easily as thinner mashes.
No, that doesn’t seem right.
Kai
This makes sense if they are talking about making beers of the same gravity. They’ll be leaving a lot of sugar behind in the mash tun by doing a single batch sparge, but can easily get as much sugar in the boil kettle as doing two batch sparges with less grain. I don’t know if that is what they’re talking about though.
I think I figured out what they are trying to tell me.
10 lbs grain 10 gallon batch 1 quart per lb= 2.5 mash 8.8 sparge
20 lbs of grain 10 gallon batch 1 quart per lb=5 gallons mash 7.6 sparge
30 lbs grain 10 gallon batch 1 quart per lb=7.5 gallons mash 6.4 sparge
40lbs grain 10 gallon batch 1 quart per lb=10 gallons mash 5.2 sparge
so as the grain weight goes up the mash volume increases and the sparge volume decreases
Looking at it like this makes sense but still doesn’t seem right.
I really need to find a job so I will stop obsessing over this stuff. 
The general rule that I use for a five gallon batch. Add an extra gallon for every 10lbs of grain and another gallon for each hour of boil time. So for a five gallon batch of beer using a total of ten pounds of grain.
5gal + 1gal/10lbs grain + 1gal/hour of boil time = 7gal total water volume
Keep in mind that this calculation is a rough estimate. Hops will also retain some water as well.
I typically split the total water 50/50 between the mash and the sparge.
How about for a 10 gallon batch?