calcualting mash and sparge water (batch sparge)

[wxman73]

Hi All,

I've been doing BIAB for almost a year now, but I'm making the leap to all grain with a regular mash. I plan to batch sparge. I have a 10 gallon cooler turned mash tun. I plan on brewing a Weizenbock with an OG of 1.081. The grain bill comes to 18.25 lbs for a regular 5 gallon brew. I want about 7 gallons pre-boil (doing a 90 minute boil). I'm a little confused as to how to calculate how much water A) mash with and B) sparge with. Is it 2 quarts per lb? And if so is that just for the mash, or for the mash and the sparge, using half the water for each?

Thanks!

 

[Hebby5]

It's typically 1.25 quarts per pound for mash water but I usually round up based on my water pitcher (1/4 Gal. increments). After hour ( I do 45), I do a 1G "mash out" at 180+ deg F, then run off. That's your 1st running. You might want to measure on a stick 1 gallon increments into your brew pot. If you want 7 G total, subtract your 1st runnings and that's what you should add to the mash tun. Mix and then drain your 2nd runnings. There are lots of videos out there on YouTube that describe the process better than this but that should get you started. Good luck!

 

[wxman73]

easy to understand. Thanks Hebby!

 

[Yooper]

I generally mash with 1.5 quarts of water per pound of grain, but anywhere in 1.25-2 quarts per pound will do.

In your example, using 18.25 pounds of grain, I'd use 27 quarts of water. However, I'm sure that the MLT would be pretty full so you could always start with less just in case you have to add some extra hot water (or ice) to hit your mash temp. Call it 24 quarts if you'd like- then it's a nice even 6 gallons and that makes it easier to measure.

Grains will absorb approximately .125 gallons of water in the mash per pound of grain- so right there you'll "lose" 2.25 gallons out of the mash.

So, if you mash in with 6 gallons, and the grain absorbs 2.25 gallons, you'll need approximately 3.25 gallons of sparge water. One tip is to actually measure your first runnings when you drain your MLT before sparging. Then you will know exactly how much sparge water to use, as the grains won't absorb any more liquid once saturated.

Generally, for optimum efficiency I've found that making the mash and sparge runnings about equal will work very well.

 

[Denny]

I generally mash with 1.5 quarts of water per pound of grain, but anywhere in 1.25-2 quarts per pound will do.

In your example, using 18.25 pounds of grain, I'd use 27 quarts of water. However, I'm sure that the MLT would be pretty full so you could always start with less just in case you have to add some extra hot water (or ice) to hit your mash temp. Call it 24 quarts if you'd like- then it's a nice even 6 gallons and that makes it easier to measure.

Grains will absorb approximately .125 gallons of water in the mash per pound of grain- so right there you'll "lose" 2.25 gallons out of the mash.

So, if you mash in with 6 gallons, and the grain absorbs 2.25 gallons, you'll need approximately 3.25 gallons of sparge water. One tip is to actually measure your first runnings when you drain your MLT before sparging. Then you will know exactly how much sparge water to use, as the grains won't absorb any more liquid once saturated.

Generally, for optimum efficiency I've found that making the mash and sparge runnings about equal will work very well.

All of this^^^^. At the beginning, don't worry about equal runnings from your mash and sparge. It doesn't make a huge difference. Do it empirically by measuring your mash runoff. After a few brews you have a handle on your equipment and you can start doing calculations in the future. After 16 years and 452 batch sparge mashes, I do the calculations, but I still do the measurement and adjust the calculated sparge amount based on reality!

 

[wxman73]

Yooper and Denny thanks so much. I will go with the calculations as my plan but measure as i go to make sure i end right. Hopefully ill be about equal mash volume to sparge volume. I am doing this this coming weekend. I feel i have a strong understanding now. Thanks!


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[Denny]

If you haven't already, take a look at www.dennybrew.com

 

[wxman73]

Thanks Denny, great info there!


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[wxman73]

Just finished my brew session. Started with 6 gallons for my mash. Ended up with 4 gallons after first runnings. I added 3.5 gallons sparge. Nailed my gravity. And after boil off i had just over 5.5 gallons. Thanks again to all!


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