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yournotpeter · 03-12-2009, 02:52 AM

Good Evening Folks -

Doing my first AG Saturday and I'm stoked. But I do have a question on the amount of water I will be using. I am doing a Robust Porter asking for 11 lbs of grain. Using John Palmer's ratio of 1.5 - 2.0 quarts/lb for mash and roughly 1/2 gallon/lb for sparge this gives me a total of up to 11 gallons of water. Now, I realize a lot of water remains in the mashed grains, but I have an 8 gallon brewpot, which I'd like to fill with 7.5 gallons (at the most) of wort. Am I in trouble here or will I be OK? Any suggestions....

Thanks much!

**ajf** · 03-12-2009, 03:23 AM

Palmer favors thin mashes. You can actually mash as thick as 1 qt/lb.
Grain absorption accounts for about 1 pt/lb.
So with 11 lb grain, mashed at 1 qt/lb and sparged with 2 qt/lb, you would collect 6.875g wort.

with an 8g kettle, I don't think I would like to boil more than that.

-a.

luvmy40 · 03-12-2009, 01:01 PM

I hit my best efficiency with 1.25 qt/lb strike and 2qt/lb sparge. I am batch sparging and split the 2qt/lb evenly in 2 sparges.

**Bobby_M** · 03-12-2009, 02:02 PM

The idea of a fixed ratio for sparge is kinda flawed because it ignores desired preboil volumes.

1. Decide finished batch size.
2. Determine boil time 60m or 90m for Pils malts.
3. Factor in typical boil off rate 1-2gallons per hour.

Just as an example, I boil off about 1.5gph. I want 5.5 gallons in my fermenter. I leave about half gallon in my kettle and chiller. So, 5.5 + .5 + 1.5 (for 60m boil) = 7.5 gallons preboil.

Starting with a fixed preboil volume, take your mash liquor volume minus .12g per pound. That's what you should collect from first runnings. Now subtract that from your desired preboil volume and that is your sparge volume.

In your robust porter with 11lbs of grain:

11lbs x 1.5qts/lb = 16.5 quarts.... round down to 4 gallons of strike water.

11lbs x .12g/lb = 1.32 gallons lost to absorption. 4g - 1.32g = 2.68 gallons first runnings collected.

If you want to start with 7 gallons preboil, 7 - 2.68 = 4.32 gallons of sparge. One way to correct for errors in calculation is to actually measure the first runnings volume.

sirsloop · 03-12-2009, 06:04 PM

...try doin that after a 6 pack....

**Bobby_M** · 03-12-2009, 06:22 PM

Quote:

Originally Posted by sirsloop

...try doin that after a 6 pack....

or 3 ounces of your 120min clone.

yournotpeter · 03-12-2009, 09:27 PM

Thank you much, folks! I appreciate the advice!

Champurrado · 03-12-2009, 11:55 PM

Also, if you're worried about the 7.5 gallons pre-boil in an 8 gallon kettle, you should be fine. I filled my brew kettle almost to within an inch of the top this past saturday and, so long as I watched the gas, I was able to boil without boil overs.

Good luck!

**AZ_IPA** · 03-13-2009, 02:58 AM

Quote:

Originally Posted by Bobby_M

The idea of a fixed ratio for sparge is kinda flawed because it ignores desired preboil volumes.

1. Decide finished batch size.
2. Determine boil time 60m or 90m for Pils malts.
3. Factor in typical boil off rate 1-2gallons per hour.

Just as an example, I boil off about 1.5gph. I want 5.5 gallons in my fermenter. I leave about half gallon in my kettle and chiller. So, 5.5 + .5 + 1.5 (for 60m boil) = 7.5 gallons preboil.

Starting with a fixed preboil volume, take your mash liquor volume minus .12g per pound. That's what you should collect from first runnings. Now subtract that from your desired preboil volume and that is your sparge volume.

In your robust porter with 11lbs of grain:

11lbs x 1.5qts/lb = 16.5 quarts.... round down to 4 gallons of strike water.

11lbs x .12g/lb = 1.32 gallons lost to absorption. 4g - 1.32g = 2.68 gallons first runnings collected.

If you want to start with 7 gallons preboil, 7 - 2.68 = 4.32 gallons of sparge. One way to correct for errors in calculation is to actually measure the first runnings volume.

What Bobby_M said! +1 (then again I'm biased because I'm a Bobby_M N.M.O.D.B.S. disciple)

Indy418 · 03-13-2009, 10:02 PM

+1 on Bobby again. I just did my first AG mini-mash using Deathbrewer's stovetop tutorial. Calculated my sparge based on my boil volume and hit all my numbers perfecto!