calculating efficiency beersmith vs by-hand - Home Brew Forums

 Home Brew Forums > calculating efficiency beersmith vs by-hand

01-24-2009, 03:39 AM   #1
mummasan
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Feb 2007
O'ahu
Posts: 235

I don’t have beersmith so I have been doing my efficiency calculations by hand using Palmer’s book ‘How to Brew’ as a guide. Recently, when I asked a brewing buddy to put a recipe into beersmith I discovered that my hand calculations don’t match beersmith’s numbers. I’m sure I am doing something wrong and I would like to figure out what it could be. I was hoping another brewer could help me out.

This is the recipe: 7.5 lbs maris otter, 3.5 lbs two-row and 1.5 lb wheat – collected 6.5 gallons of wort and had a 1.060 BG gravity.

In one of the chapters in Palmer’s book, What to expect when you’re extracting, he assigns points to various grains. For max efficiency, he gives 38 points for two-row, 37 points for wheat and he does not assign a value for Maris Otter so I guessed 37 for Maris. Palmer says to multiply the points per pound then divide by the amount of wort collected into the kettle (38 x 3.5, 37 x 9 = 466 then divide by 6.5 = 71.6). Palmer says this is the max extraction efficiency from these grains – 1.071. (Someone let me know if I am wrong).

The 6.5 gallons of wort that I collected in my kettle had a BG of 1.060. Palmer says to divide 60/71 and you get your efficiency – for this brew day I calculated 84.5% efficiency.

The beersmith calculation my brewing buddy did said I got 73% efficiency. That is quite a difference. What am I doing wrong?

Palmer also indicates that you can calculate your efficiency by points per gallon. I calculated that with 12.5 lbs, collecting 6.5 gallons into my kettle and a OG of 1060 I got 31 points per gallon from my mash. Apparently anything over 30 is good. Does anyone else calculate their points per gallon? Have I calculated this wrong too?
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01-24-2009, 04:02 AM   #2
Kaiser

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Nov 2005
Pepperell, MA
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Make sure that 6.5 gal is set as the batch size in Beersmith Then the brewhouse efficiency should match what you have.

Also check the extract % numbers that Beersmith has for the grains. They should be around 80%. But my guess is that it is taking the wrong volume for the efficiency calculation.

~85% efficiency is what I came up with. So you seem to be on the right track.

Kai

01-24-2009, 05:43 AM   #3
mummasan
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Feb 2007
O'ahu
Posts: 235

Its good to know I'm on the right track...even though I have never liked math I enjoy calculating my efficiency and IBUs because it all relates to beer!
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01-24-2009, 06:03 PM   #4
FlyGuy

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Calgary, Alberta
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Your hand calculations are fine. I think your problem is how you are using/interpretting Beersmith.

Beersmith calculates efficiency a few different ways. Which one did you use? Most people use the calculation based on Beersmith's predicted target volume (this is the volume of wort AFTER boiling and cooling -- i.e. batch size) and their post-boil gravity. I suspect your buddy may have confused something here (e.g., used your post-boil volume but entered the pre-boil gravity). That is easy to confuse -- in fact I think even Kaiser did that above (your batch size to be entered into Beersmith was probably something like 5.5 gals, NOT 6.5 gals which is the pre-boil volume).

Also note that he may have calcluated Brewhouse efficiency based on volume and gravity into the fermenter. If he did this, then this calculation takes kettle losses into consideration as well (e.g., losses of wort in the kettle, in the chiller, or to hop absorption). Your hand calculation does not do this, and if you have an significant losses going to the fermenter, it would not be surprising to see a 10% loss in efficiency. That could be correct.

Beersmith also has a tool to calculate your pre-boil efficiency in a way similar to your hand calculations, and that should be most comparable. Tell your buddy to go into the recipe (Recipe View) and click on the button labeled Brewhouse Efficiency. I dialog will pop up, and look to the middle for the section labeled 'Efficiency into Boiler'. Enter in your pre-boil volume (6.5 gal) and pre-boil gravity (1.060). Based on your recipe, Beersmith tells me that your efficiency was 83.3%. The small difference here is due to slightly different yields in Beersmith and rounding errors.

01-24-2009, 06:25 PM   #5
mummasan
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Feb 2007
O'ahu
Posts: 235

Thanks for the detailed response.

On another note, I used your pictures of the 'Cheap 10 gal cooler MLT' to build my MLT. So far mine works great! Thanks.
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01-24-2009, 08:25 PM   #6
FlyGuy

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Quote:
 Originally Posted by mummasan Thanks for the detailed response. On another note, I used your pictures of the 'Cheap 10 gal cooler MLT' to build my MLT. So far mine works great! Thanks.

10-11-2010, 09:23 PM   #7
Indyking
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Aug 2010
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This is an old thread and the problem seems to be resolved, thanks to the nice response by FlyGuy; however, I need help with the same topic if someone can help me.

My question is simple. How do I know the amount of wort collected into the kettle (boiler) to be able to calculate the efficiency? Is it the same as the amount of water going into the system during mashing and sparging? If yes, how about the water losses during the process (since the grains absorb some water and the mash tun may retain some too depending on the system)?

If I put 6.5 gallons of water in the system to mash and sparge, I will never be able to recover the same 6.5 gal, so what volume should I use for calculating efficiency? It's not possible to measure the amount of wort in my kettle, so I'm not sure!

10-12-2010, 01:46 PM   #8
Jesper
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Ljusdal, Sweden
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Quote:
 Originally Posted by Indyking It's not possible to measure the amount of wort in my kettle, so I'm not sure!
Make yourself a measuring stick and use it to estimate the volume in your kettle with a fair accuracy.

If your kettle is really odd shaped so it's practically impossible to calculate volume based on the level on your measuring stick you can pour a gallon of water into your kettle, make a mark on your stick where the level is, pour another gallon of water into you kettle, make another mark on your stick etc.

10-12-2010, 10:28 PM   #9
Indyking
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Quote:
 Originally Posted by Jesper Make yourself a measuring stick and use it to estimate the volume in your kettle with a fair accuracy. If your kettle is really odd shaped so it's practically impossible to calculate volume based on the level on your measuring stick you can pour a gallon of water into your kettle, make a mark on your stick where the level is, pour another gallon of water into you kettle, make another mark on your stick etc.
That's a good idea but after hearing a podcast by John Palmer, it seems that, in order to calculate efficiency, we should always take into consideration the amount of water poured into the system (mash plus sparging) and never the amount collected in the kettle (boiler). The reason for that is because efficiency is also a measure of how much of the water added was recovered as wort through the system. In fact, according to what I understood, one of the most common causes of poor efficiency is wort retention in dead spaces created in the mash tun due to a poorly configured system or poor handling of the grain bed during infusion. That makes sense. Did I understand everything correctly?

10-13-2010, 12:13 AM   #10
Walker
I use secondaries. :p

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Cary, NC
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Quote:
 Originally Posted by Indyking we should always take into consideration the amount of water poured into the system (mash plus sparging) and never the amount collected in the kettle (boiler). The reason for that is because efficiency is also a measure of how much of the water added was recovered as wort through the system. In fact, according to what I understood, one of the most common causes of poor efficiency is wort retention in dead spaces created in the mash tun due to a poorly configured system or poor handling of the grain bed during infusion. That makes sense. Did I understand everything correctly?
There are many different "efficiencies" that people measure.

Measuring the amount of wort in the kettle is how you get your overall "brewhouse" efficiency. That number factors in your volume losses in the tun.
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