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Joe028 11-29-2006 12:20 PM

First AG calculations
 
I have a new keggle and 5 gal cooler with SS braid and am trying to attempt an AG Saturday. It is a Dry Stout with 10.75 lbs of grain.

I realize it has a lot to do with my system, but Iím having a hard time grasping the amount of water I will need for this. Recipe calls for 1qt/lb, 6.25gal wort total, boil down to 5.25gal. Using BeerSmith, I was thinking more on the lines of 1.25 qt/lb, 6gal wort total, boil down to 5 gal.

BeerSmith has me doing 2 ďroundsĒ of sparging I assume because the amount of sparge water plus grain wonít fit in a 5 gallon cooler. For those of you with the 5 gallon cooler do you do this, or do you mash with more water to lessen the amount of sparge water needed? I have read so much more about doing just one sparge and am a little weary about 2 separarate sparges.

Also, if Iím trying to figure this out with 10.75 pounds of grain, how is it that some on this forum are using the 5gal cooler with up to 12-14lbs of grain? Thanks

Joe

Walker 11-29-2006 01:24 PM

Quote:

Originally Posted by Joe028
BeerSmith has me doing 2 “rounds” of sparging I assume because the amount of sparge water plus grain won’t fit in a 5 gallon cooler. For those of you with the 5 gallon cooler do you do this, or do you mash with more water to lessen the amount of sparge water needed? I have read so much more about doing just one sparge and am a little weary about 2 separarate sparges.

I'm new to AG brewing, but I did a lot of research on it before attempting it the first time... specifically, I read a lot about batch sparging.

Every source source I found said that you want your initial run-off volume and your batch sparge run-off volumes to be equal.

At first, I thought this implied that you needed to do one round of sparging. However, some other sources I read indicated that you want your initial run-off to be half of the total volume, and your sparge run-off (which can be done in multiple batches) to make up the other half of the volume.

This is a moot point for me b/c I have a 10 gallon cooler, but from what I have read you should be OK doing multiple rounds of sparging.

Here's a quote from http://hbd.org/cascade/dennybrew/
Quote:

Originally Posted by dennybrew

R1=initial runoff volume which = mash water volume - water absorbed by grain

(assumed to be .1 gal./lb. for this example since that’s the way my system works...use your own figure)

S= batch sparge water volume
V= total boil volume (amount in needed in kettle for boil)
I=volume of infusions for a step mash

R1+I+S(1)+S(2)+S(etc.) must equal V

AND
R1+I=.5V



Orfy 11-29-2006 02:20 PM

If you use equal volumes for mash and sparge then tour first run of will possible be half your second run off due to dead space in the mash tun and absorption.

Walker 11-29-2006 02:49 PM

Quote:

Originally Posted by orfy
If you use equal volumes for mash and sparge then tour first run of will possible be half your second run off due to dead space in the mash tun and absorption.

That's kind of where the "I" in the equations comes in.

When I did my AG a few weeks ago, I faked a "mash-out" and added more water (the "I" amount) to my mash before taking the first runnings so that my initial run-off (R1+I) and sparge run-off (S1) were equal volumes (0.5V).

Orfy 11-29-2006 03:13 PM

Yep that sounds right to me. But I think it's more important to set the mash volume by the water to grain ratio. (1.5-2q/lb)

So for a typical grain bill of 10lb then you'll mash with 20qt
Typical absorption of 0.10 gallons/lb = 1 gallon
Plus dead space say 2.5 qt

Equals first run off of 20qt - 6.5qt = 13.5qt
That means your second run of needs to be 14.5qt
Depending on post boil wort required

Your gonna get some further absorption on the 2nd run of so I say the sparge amount needs to be 17qt.

Now that's not far of 50/50.

Forgive me if I got something wrong. I use Litres and and KGs. plus uk and us gallons are different.

Blender 11-29-2006 03:14 PM

I have done about 10 all grains batch sparged beers and here is what I have learned in the process. As a general rule you want to do 2 sparges and get about the same volume from both.

In the initial few batches you will learn about how your system works. You will need to know how much evaporation occurs during a one hour boil, you have to figure for grain absorbtion and dead space in your equipment. Your effeciency is usually not the best on the first try.

I don't think it would make a great deal of difference whether you use 1 or 1.25 quarts of water per gallon for your initial mash infusion. I use 1.2 quarts per pound. I have found that the grain absorbs roughly .12 quarts per pound. I have about a pint of dead space that will not drain no matter how high I tilt the cooler.I would also plan on a finished wort of 5.5 gallons which should yield a good 5 gallons of finished beer come bottling or kegging time.:mug:

Let's say you want 7 gallons of wort to boil.

1. 10.75 * 1.25 = 3.35 gallons of strike water.
2. The grain absorbs 10.75 * .12 = 1.3 gallons
3. 3.35-1.3 = 2.05 which means you will need to add 1.5 gallons of 185-190 degree water at the end of the 60 minute mash to yield 3.5 gallons for the first runnoff. This gets the grain temp up a bit. Stir thoroughly for 3-5 minutes and then begin the runoff. Make sure the runoff runs clear before you collect the wort in the kettle. Vorlauf it. :)
4. The second runoff is just 3.5 gallons to get to the 7 gallon mark. I usually have the water at around 185 degrees and stir thoroughly before the runoff.

Hope this helps and my math is right.

Orfy 11-29-2006 03:28 PM

You've got to watch that you don't let the run off SG drop too low.
Better to add water to the boil rather than run it through the grain and risk extracting to many tannins.

If you find your efficiency's not up to scratch then think about...

Adding a little Malt extract, Reducing the Brew volume.
Next time figure out why the efficiency was low or increase the grain bill.

Batch sparging recipes seem to have 1/3 extra grain.

ajf 11-29-2006 11:44 PM

Quote:

Originally Posted by Joe028
Also, if Iím trying to figure this out with 10.75 pounds of grain, how is it that some on this forum are using the 5gal cooler with up to 12-14lbs of grain? Thanks

Joe

Simple answer is I fly sparge where you continually add sparge water as you drain the wort. With this technique, you need very little space in the tun, but batch sparging is probably easier (and definitely quicker) especially if there is enough space in the tun for the sparge water.

-a.


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