Completed first AG - Need help with Calculations - Home Brew Forums

 Home Brew Forums > Completed first AG - Need help with Calculations

11-19-2007, 05:42 AM   #1
Acropolis
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Oct 2007
Posts: 9

I completed my first AG batch today. To be honest with you, I wasn't sure of all of the readings/calculations that would be needed, so I took multiple. I was hoping someone could help me sort it all out. I have sliced and diced everything multiple ways and fear that my efficiency wasn't that great, but I am not really sure.

I brewed a recipe I found on the internet and loaded into Brewsmith:

Joes Irish Red Ale

12 oz barely, flaked
1.9 oz Chocolate (Crisp)
3.0 oz Crystal Dark
9 lbs Maris Otter (Crisp)

I mashed in a 10 gallon igloo cooler with 3.25 gallons of water at 152 degrees for 60 minutes and then took a gravity reading of 1.068.

I then batch sparged with 4.75 gallons of water at 165 degrees (probably should have split it into 2 sparges) and then took a gravity reading of 1.040. (I have since read that I should have been closer to 1.020 after collecting the final runnings).

I finally ended up with just under 7 gallons of wort to boil (slightly more than I would have liked). After boiling for 90 minutes to get it down to 5 gallons, I ended up with a gravity reading of 1.048.

1) Would splitting my sparges into 2 halves improved efficiency (lowering my readings closer to 1.020)?

2) Am I correct in calculating that my gravity reading pre-boil is [(68*3.25)+(40*4.75)/8=51 (1.051)? I have no idea if you can calculate it that way.

3) For my post-boil gravity I measured 1.048. Is this the number I use as original gravity? How do I calculate my efficiency? The recipe estimated a pre-boil gravity of 1.048 and a post-boil gravity of 1.055.

Any help that could be provided sorting all this out would be greatly appreciated. I am not even sure where to start on improving my processes before my next batch. Hopefully these numbers will tell me if I did a terrible job.

Acropolis

11-19-2007, 11:52 AM   #2
Jekster
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Jun 2007
Bloomington, IN
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Download a trial copy of beersmith or promash and create a recipe with those grains. You can then see what the estimate OG is at a certain efficiency and keep changing that until you hit what you actually got post boil given your volume. Much easier than doing the math by hand.
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11-19-2007, 12:04 PM   #3
Acropolis
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Oct 2007
Posts: 9

Quote:
 Originally Posted by Jekster Download a trial copy of beersmith or promash and create a recipe with those grains. You can then see what the estimate OG is at a certain efficiency and keep changing that until you hit what you actually got post boil given your volume. Much easier than doing the math by hand.
I actually have a trial copy of beersmith and have loaded a copy of the recipe (the recipe I used came in a beersmith format). I'm just not sure if I am making the right adjustments for it to do the calculations.

Are my assumptions for combining the two gravities correct (1.051)? I put This along with my pre-boil water volume and the pre-boil gravity (1.048) into beersmith and it calculated an efficiency of 62.05%. Does that sound correct? I just want to make sure the way that I am entering the correct numbers. I am also trying to understand how they are calculated.

Once I understand what my efficiency was, I can work on improving it.

11-19-2007, 01:26 PM   #4
Yooper
Ale's What Cures You!

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Jun 2006
UP of Michigan, Winter Texan
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You said that your post boil gravity was 1.048. That is your og if that is what you read going into the fermenter at 60 degrees (temperature corrected). You don't calculate your og from the other ogs that you take- you just take it and figure the efficiency from there.

Beersmith makes it super easy to do. You just put the number in and it calculates it for you.
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11-19-2007, 02:27 PM   #5
Acropolis
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Oct 2007
Posts: 9

Quote:
 Originally Posted by YooperBrew Beersmith makes it super easy to do. You just put the number in and it calculates it for you.

I think I have it figured out in Beersmith. It calculates an efficiency of 62%. I'm not sure how good that is for a first try, but I am not going to complain. If the beer tastes good, I will be happy.

11-19-2007, 02:51 PM   #6
Yooper
Ale's What Cures You!

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Jun 2006
UP of Michigan, Winter Texan
Posts: 69,883
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Taste is the most important thing! I'm glad your first batch went so well for you!
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11-19-2007, 02:55 PM   #7
eviljafar

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Jul 2007
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62% efficiency is OK. Of course the higher it is the less grain you'll need, but to be honest I think some people get a little obsessed over efficiency. What you really want to aim for is consistent efficiency across batches. Then you can adjust recipes to suit your brewhouse and your beer will turn out as intended.
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11-19-2007, 03:01 PM   #8
BierMuncher
...My Junk is Ugly...

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Jan 2007
St. Louis, MO
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Quote:
 Originally Posted by Acropolis I think I have it figured out in Beersmith. It calculates an efficiency of 62%. I'm not sure how good that is for a first try, but I am not going to complain. If the beer tastes good, I will be happy.
I have you at 68% which is fine by anyones standards and great your first time out.

With Beersmith, you enter the ingredients...and then adjust the efficiency until you get to the gravity you ended up with.

It's kind of like backwards solving...