# Homebrewers Association | AHA Forum

## General Category => All Grain Brewing => Topic started by: etbrew on October 17, 2010, 09:45:33 AM

Title: How much mash water do I use???
Post by: etbrew on October 17, 2010, 09:45:33 AM
I'm brewing my second all grain batch today.  I'm doing my water calculations and I can't figure out what to do ??? .  My first batch was a low gravity brown ale I mashed using a ratio of 2 quarts water to 1 lb of grain.  That ratio on that batch yielded me almost exactly half the boil volume so I sparged with an equal amount of water.

The batch I'm brewing today is a higher gravity porter.  It has 13lbs of grain and at 2 quarts to 1 lb of grain that gives me 6.5 gallons of mash water.  I'm going to loose a gallon or so to the grain which would leave me needing to sparge with 1 gallon to reach a boil volume of 6.5 gallons.

I've read different numbers on mash water ratios from 2 quarts per pound down to 1 quart per pound.  What should I use for a water grain ratio?
Title: Re: How much mash water do I use???
Post by: hopfenundmalz on October 17, 2010, 12:13:11 PM
One of the common ratios you will see is 1.25 qt./lb.  If you use that you will be able to up your sparge water volume.

Title: Re: How much mash water do I use???
Post by: etbrew on October 17, 2010, 12:24:44 PM
One of the common ratios you will see is 1.25 qt./lb.  If you use that you will be able to up your sparge water volume.

Thanks for the response.  I've been thinking 1.25 qt/lb.  Are there any drawbacks to a thicker mash?  How can I calculate what temp the strike water needs to be to reach a mash temp of 156 degrees?
Title: Re: How much mash water do I use???
Post by: tygo on October 17, 2010, 12:39:53 PM
A thicker mash is a bit harder to stir and make sure all the clumps have been broken up, otherwise it's fine.

The formula for calculating your (Fahrenheit) strike water temp is [0.2/Water-to-grain ratio x (Target Mash temp - Grain temp)] + Target Mash temp

So if you're grain temp was 70F and your target mas temp was 156F and you're using 1.25 gallons per pound it would be:

[(0.2/1.25) x (156-70)] + 156 = 169.76

Just remember to account for any thermal loss to the mash tun.  Sounds like you're batch sparging.  If you're using a cooler you'll lose a good amount of initial strike water heat to the thermal mass of the cooler.  I usually add the water first and shoot for a water temp 10-15 degrees above my desired strike water temp and let it sit for a few minutes to heat up the mash tun.

Also, you're probably going to lose a little more than a gallon to 13 lbs of grain.  The common convention is about 0.12 gallons per pound of absorption which in this case would be about 1.5 gallons.

Title: Re: How much mash water do I use???
Post by: etbrew on October 17, 2010, 12:51:00 PM
A thicker mash is a bit harder to stir and make sure all the clumps have been broken up, otherwise it's fine.

The formula for calculating your (Fahrenheit) strike water temp is [0.2/Water-to-grain ratio x (Target Mash temp - Grain temp)] + Target Mash temp

So if you're grain temp was 70F and your target mas temp was 156F and you're using 1.25 gallons per pound it would be:

[(0.2/1.25) x (156-70)] + 156 = 169.76

Just remember to account for any thermal loss to the mash tun.  Sounds like you're batch sparging.  If you're using a cooler you'll lose a good amount of initial strike water heat to the thermal mass of the cooler.  I usually add the water first and shoot for a water temp 10-15 degrees above my desired strike water temp and let it sit for a few minutes to heat up the mash tun.

Also, you're probably going to lose a little more than a gallon to 13 lbs of grain.  The common convention is about 0.12 gallons per pound of absorption which in this case would be about 1.5 gallons.
Thanks for the info.  The formula and the absorption ration are a big help and yes I'm batch sparging with a cooler.  I'm heating the strike water right now...

Title: Re: How much mash water do I use???
Post by: dmtaylor on October 17, 2010, 02:27:38 PM
By my calculations, the 13-lb mash would soak up about 1.3 gallons of water (0.1 gal/lb), and your efficiency would be maximized by going with a water to grain ratio of 1.5 qts/lb, so that you would need 4.9 gallons to strike, and then approximately 3.3 gallons to sparge.  Every system is a little different, but experience says for me and my system that this would put me within 1 quart of my desired final volume.

I also try to monitor volumes in the kettle towards the end of the boil as well.  If your kettle is pre-marked with volumes quart-by-quart as mine is, you can do this too.  Occasionally I boil longer or shorter to try to adjust volume directly in the kettle.

Don't forget to account for all your water losses, which include liquid lost in the mash tun, the hot and cold break, and trub and samples in the fermenters.  All those things can add up to a good 2 to 3 quarts.  So if you want to end up with 5 gallons of beer, after the boil you really need somewhere around 5.5 gallons.  My calculations above have already taken these losses into account, at least for MY system.

Good luck.  Let us know how it turns out for you.
Title: Re: How much mash water do I use???
Post by: svejk on October 17, 2010, 05:52:57 PM
Even though I am fairly good at math, I rely completely on Promash for my calculations. There will be times when I want a thicker mash or a longer boil, and it will change everything for me. If you're open to the idea, I highly recommend investing in brewing software.
Title: Re: How much mash water do I use???
Post by: beveragebob on October 17, 2010, 10:29:02 PM
I start with how much wort I want to end up to ferment                      5.5 gallons
Then I add grain absorption  (say i'm using 10 lbs) .1 gal/lb                1 gallon
Evaporation per hour.... my system is ~ 1.66 gallons p/h for 90min   ~2.5 gallons
I usually add another half gallon to account for system loss's
i.e wort left behind in lauter tun / boil kettle                                          .5 gallons

So I use 5 gallons of water in the mash tun and ~ 4.5 gallons in the HLT for sparging and I always get ~ 5.5 gallons in my fermenting buckets.

HTH
Title: Re: How much mash water do I use???
Post by: etbrew on October 17, 2010, 11:26:04 PM
Thanks for all the tips.  I was a little worried when I woke up this morning but everything worked out.

I used 1.25 qt/lb at 175 degrees (a little high to account for heating of cooler) to shoot for mash temp of 156.  I ended up with a mash temp of 153 so I added some hot water to raise temp (next time I'll preheat the mash tun).  Planned for 1.5 gallons of absorption from the grain so sparged with 4 gallons to get a boil volume of between 6.5 and 7 gallons.  I boiled an extra 15 minutes to get to a volume of about 5.5 gallons or maybe a little less.  I am surprised that I ended up within one point of my target gravity.  I can't wait to taste it  ;D
Title: Re: How much mash water do I use???
Post by: 1vertical on October 28, 2010, 03:28:56 PM
Tell John I sent you.  There is a link on this site for mashwater software by
a great acquantance of mine.  I could not brew all grain well without his help.
Highly recommend.
http://gnipsel.com/beer/software/beer-software.html (http://gnipsel.com/beer/software/beer-software.html)
Title: Re: How much mash water do I use???
Post by: denny on October 28, 2010, 03:39:17 PM
If you;re batch sparging, this is the easy way to figure out water requirements...mash with whatever ratio you like.  I generally go for 1.3-1.75 qt./lb.  After you run off your mash, measure how much you have in your kettle.  Subtract that from the amount you want to boil.  The answer you get is the amount of sparge water ti use.
Title: Re: How much mash water do I use???
Post by: kgs on October 31, 2010, 03:11:30 AM
If you;re batch sparging, this is the easy way to figure out water requirements...mash with whatever ratio you like.  I generally go for 1.3-1.75 qt./lb.  After you run off your mash, measure how much you have in your kettle.  Subtract that from the amount you want to boil.  The answer you get is the amount of sparge water ti use.

Being math-challenged, this is exactly what I do. Every time I am surprised that it works. But Denny does it, so...! (I also use at least 1.5/lb to make it easy to stir two or three times during the mash.)
Title: Re: How much mash water do I use???
Post by: tubercle on October 31, 2010, 03:29:38 AM
If you;re batch sparging, this is the easy way to figure out water requirements...mash with whatever ratio you like.  I generally go for 1.3-1.75 qt./lb.  After you run off your mash, measure how much you have in your kettle.  Subtract that from the amount you want to boil.  The answer you get is the amount of sparge water ti use.

Being math-challenged, this is exactly what I do. Every time I am surprised that it works. But Denny does it, so...! (I also use at least 1.5/lb to make it easy to stir two or three times during the mash.)

Tubercle does also.

Life is too short to worry about all those details that really don't make a difference.

"There is nothing as useless as doing efficiently that which should not be done at all" - Peter Drucker.
Title: Re: How much mash water do I use???
Post by: Hokerer on October 31, 2010, 03:40:57 AM
"There is nothing as useless as doing efficiently that which should not be done at all" - Peter Drucker.

Green Acres, right?
Title: Re: How much mash water do I use???
Post by: IHBHS on October 31, 2010, 04:09:58 AM
www.beersmith.com
Title: Re: How much mash water do I use???
Post by: tubercle on October 31, 2010, 01:13:28 PM
"There is nothing as useless as doing efficiently that which should not be done at all" - Peter Drucker.

Green Acres, right?

No  ::) This is Peter Drucker the great industrialist
http://en.wikipedia.org/wiki/Peter_Drucker

You're thinking of his cousin Sam that runs the store ;D