How do i adjust mash/sparge ratio for large AG bills? - Home Brew Forums

 Home Brew Forums > How do i adjust mash/sparge ratio for large AG bills?

01-06-2012, 11:20 PM   #1
je52rm
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Dec 2011
orlando, florida
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I'm gonna be doing AG infusion mash on my next batch and i am wondering how should i adjust Mash/Sparge water ratio's to obtain expected OG of recipe but not have more than 5 gallons wort (or a bit more cause im using a glass blowoff tube) for primary fermentation in a 5 gallon glass carboy?

For example:

11 pounds grain =

2.75 gallons for mash (.25 gallon/lb. of grain)
+ 5.5 gallons for sparge (.5 gallon/lb. of grain)

= 8.25 gallons - .825 gallons (.1 per lb. of grain) for grain absorption = 7.42 gallons

7.42 gallons wort - 1 gallon boil off = 6.42 gallons ??? too much for 5 gallons

Are there any "Rule Of Thumb" Ratios i should use to obtain the correct amount after the boil?

Or should i use the ratio of (like in my examples) 6.42 gallons vs. 5 gallons???

example: 5 gallons is approx. 78% of 6.42 gallons (typical mash/sparge ratios for 11 lb. grain bill) so i can plug the 78% ratios back into the mash sparge amounts to have the correct end amount.

01-06-2012, 11:29 PM   #2
weirdboy
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First off, I would not try to ferment 5 gallons of beer in a 5 gallon container, even with a blow-off, and especially not if it's high gravity.

I am totally confused by your math. Where are you coming up with that sparge volume? Just sparge however much you need to get to the preboil volume.

You should know ahead of time the volumes of all dead spaces in your MLT and BK to get your target volume into the fermenter. You should also know ahead of time the boil-off rate on your system. Work backwards from your target volume into the fermenter.

01-07-2012, 12:08 AM   #3
je52rm
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orlando, florida
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page 283 The joy of homebrewing 3rd edition by Charlie Papazian says:

One-half gallon of sparge water is (ideally) needed to sparge each pound of grain.

is 1.056-1.057 considered high gravity???

page 224 of Clone brews 2nd edition calls for 11 lb grain bill for a 5-gallon batch of Moose Drool Brown Ale and has an OG of 1.056-1.057

The AG recipes in this book are for an infusion mash. They dont give u the water amounts for the infusion mash so i am trying to figure out if i should do a "ratio" of normal amounts (less mash water AND less sparge) or should i just do less on the sparge end so i will have the correct amount for boil?

Just out of curiosity why not ferment 5 gallons in a 5 gallon carboy? By no means am I trying to question your methods/prcedures but i did a little over 5 gallons of brown ale in a glass carboy with a glass blowoff tube and the end result was great. Also i ended up with 50 beers off that same batch that was bottled directly from primary as i dont do secondary fermentations that are uneccessary for quick maturing brown ales. As far as i understood from reading The joy of homebrewing having a blowoff tube that has a lot of krausen blow-off results in a beer with less fusel oils from bitter resins and expels excess yeast resulting in a better beer with less chance off beer headaches. Once again i am not questioning your procedures just stating what i have read.

01-07-2012, 12:16 AM   #4
Double_D

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Feb 2011
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I'd just sparge less. Then you have the amount you're looking for and less head scratching to go along with it.

01-07-2012, 12:18 AM   #5
je52rm
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ok thanks Double D! Not to overcomplicate things but by using less sparge than the book calls for am i gonna compromise hitting my projected OG?

01-07-2012, 12:22 AM   #6
Yooper
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Quote:
 Originally Posted by je52rm ok thanks Double D! Not to overcomplicate things but by using less sparge than the book calls for am i gonna compromise hitting my projected OG?
Yes, and no. Sparging less may mean getting less sugars, so you may lose a few efficiency points. Since I always just sparge up to my boil volume, I do get less efficiency with a larger grainbill. For example, on a 20 pound grainbill I might get 69% instead of my usual 72% with a 12 pound grainbill. But I can accept that, since I don't want to stand around and waste fuel boiling wort for three hours to get a 5 gallon batch. I always sparge to my boil volume.

You can simply adjust your projected efficiency down and add a pound or two of extra grain to make up for it!
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01-07-2012, 12:23 AM   #7
dezman

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I typically use a waterto grain ratio of 1.25 qts/gal for the mash. For 11 lbs of grain that equals 3.4 gallons of water for the mash. Then for the sparge I usually just have more than I need (like 7 gallons or so) and just sparge untill I get a little over 6 gallons into the boil kettle.

01-07-2012, 12:29 AM   #8
je52rm
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ok yeah thanks guys that totally makes sense! do any of u guys add DME at boil to bring a less efficient mash up to projected OG?

also does anybody adhere to the joy of homebrewing's call for .5 gallon of sparge per lb. of grain used?

01-07-2012, 12:34 AM   #9
BrewKnurd

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Quote:
 Originally Posted by je52rm ok yeah thanks guys that totally makes sense! do any of u guys add DME at boil to bring a less efficient mash up to projected OG?
Yup.

Quote:
 Originally Posted by je52rm also does anybody adhere to the joy of homebrewing's call for .5 gallon of sparge per lb. of grain used?
Like a few others that have commented, I sparge based on what it takes to get to my desired boil volume (which is calculated based on how much goes into the fermenter + boil off + whatever i think i'm going to end up leaving in the bottom of the kettle due to hop and break material).
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01-07-2012, 12:36 AM   #10
Yooper
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Quote:
 Originally Posted by je52rm ok yeah thanks guys that totally makes sense! do any of u guys add DME at boil to bring a less efficient mash up to projected OG? also does anybody adhere to the joy of homebrewing's call for .5 gallon of sparge per lb. of grain used?
You certainly can add DME if your OG is off- lots of people have had to do that on their first view AG beers.

Some people probably do "adhere" to that technique, but think of it as saying you can sparge up to .5 gallon per pound of grain, not "have to" and I think you'll find it easier to think about. Maybe in pro breweries where they are trying to extract every bit of the grain's potential out of it, when costs are concerned, that makes sense to maximum your efficiency. But spending another \$10 for propane to make up for one pound of grain isn't efficient for homebrewers.
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