Calculation questions for my first AG

Ok, I want to make an Irish red ale. The grain bill is as follows:

10 pounds British two-row malt
0.25 pounds Roasted Barley
0.5 pounds Melanoidin Malt

Ok, so I start out 10.75 pounds of grain. At a water/grain ratio of 1.25 quarts per pound, that gives me 3.36 gallons of water that I need to use as strike water. With an estimated loss of water being 0.1 gallons/pound, my mash will yield about 2.28 gallons of wort. If I am doing a full boil for an hour, though, I'll need 6 gallons of wort to start with, assuming a loss of 1 gal/hour to the boil. Therefore, I need 3.71 gallons of wort to come out of my sparge. The rule of thumb for sparging, though, is to use about 1.5 times the amount of strike water, which would give me 5.04 gallons of water for sparging. If I assume the same water loss for the sparge (which may be my mistake), I'll be left with 3.97 gallons of wort, which, when added to my first run, will yield 6.25 gallons, which is a quart high.

My questions:

1) Does all of this look kosher?

2) If not, is my assumption that water loss to the grain is the same for mash and sparge correct?

EDIT: The place where I got this is assuming 77% efficiency, which is a lot higher than I had been planning. I'll have to modify the grain bill for the final recipe, but my questions are still valid.

You will only lose water to the grain ONE TIME. Once it has soaked up all that water from the mash, it can't soak up any additional water from the sparge. The same applies to mash tun dead-space (that water you just can't drain out through the spigot). Once the deadspace is full of liquid from the mash, it can't get any more full with your sparge water.

SO... some of your initial mash water will seem to vanish. But, the full volume of sparge water you put in will be returned to you.

As for your "quart high" problem. You'll just have to boil for an additional 15 minutes to get another quart evaprated.

-walker

PS: I have a spreadsheet that, after some set-up, calculates all this stuff for you.
https://www.homebrewtalk.com/showthread.php?t=19844

ayrton said:

Ok, I want to make an Irish red ale. The grain bill is as follows:

10 pounds British two-row malt
0.25 pounds Roasted Barley
0.5 pounds Melanoidin Malt

Ok, so I start out 10.75 pounds of grain. At a water/grain ratio of 1.25 quarts per pound, that gives me 3.36 gallons of water that I need to use as strike water. With an estimated loss of water being 0.1 gallons/pound, my mash will yield about 2.28 of wort. If I am doing a full boil for an hour, though, I'll need 6 gallons of wort to start with, assuming a loss of 1 gal/hour to the boil. Therefore, I need 3.71 gallons of wort to come out of my sparge. The rule of thumb for sparging, though, is to use about 1.5 times the amount of strike water, which would give me 5.04 gallons of water for sparging. If I assume the same water loss for the sparge (which may be my mistake), I'll be left with 3.97 gallons of wort, which, when added to my first run, will yield 6.25 gallons, which is a quart high.

My questions:

1) Does all of this look kosher?

2) If not, is my assumption that water loss to the grain is the same for mash and sparge correct?

Click to expand...

Walker-san said:

You will only lose water to the grain ONE TIME. Once it has soaked up all that water from the mash, it can't soak up any additional water from the sparge. The same applies to mash tun dead-space (that water you just can't drain out through the spigot). Once the deadspace is full of liquid from the mash, it can't get any more full with your sparge water.

SO... some of your initial mash water will seem to vanish. But, the full volume of sparge water you put in will be returned to you.

As for your "quart high" problem. You'll just have to boil for an additional 15 minutes to get another quart evaprated.

-walker

PS: I have a spreadsheet that, after some set-up, calculates all this stuff for you.
https://www.homebrewtalk.com/showthread.php?t=19844

Click to expand...

Thanks! You rule.

I wouldn't stress too much about an "extra" quart until you learn your system. The 0.1 gallon/lb absorbed by the grain is just an estimate, and you'll need to elarn your boil-off rate. Plus, I tend to shoot for more than 6 gallons going into the kettle, I usually start at 7 or so and land at 5.5 after an hour's boil.

Add some additional hot water at the end of the mash to account for absobtion and dead space. That way you will be closer to runnings that are equal. For what its worth I found absorbtion to be closer to .15 than .1 when I first started.

ayrton said:

Thanks! You rule.

Click to expand...

If you already grabbed that spreadsheet, grab it again. I put the latest version of it up on the website.

Also, what blender says is correct. the spreadsheet calculates this as "mash out" water. You add it in and stir the mash a couple of minutes before draining. The first runnings you get should be 50% of the total runnings. The batch-sparge will yield the other 50%.

-walker