Questions about my brewhouse efficiency calculations

[TravelingLight]

When I brewed this weekend, I finally remembered to take preboil gravities (and everything else you can think of) to determine my efficiency. I was just curious and wanted to see if I can improve it.

Grist:
11# 2-Row
2# Flaked Oats
1.5# White Wheat

I typically use the Brewer's Friend calculator for my recipes: http://www.brewersfriend.com/homebrew/recipe/calculator/

Also, when I do my calculations in the calculator, I set my efficiency at 65% because when I first went to AG last year, I missed numbers, someone suggested dropping efficiency to 65% and I've hit my numbers pretty spot on since then.

My target preboil volume is 7.5 gallons. Putting the grist and info into the recipe calculator, it had OG coming in at 1.057 (with the efficiency set at 65%). My actual OG was 1.060, so pretty dang close. My preboil gravity was 1.054.

Then, I ran my efficiency calculations. I think I used Brewer's Friend to calculate efficiency as well: http://www.brewersfriend.com/brewhouse-efficiency/

My efficiency came in at 75.3%. First question, does that sound right? Second question, does that mean that I really hit 75%, or is that off because I was calculating my predicted gravity at 65% efficiency?

I'm just getting confused by calculating my recipe at 65% but my efficiency coming in at 75%. Can anyone enlighten me? Thanks.

 

[ajdelange]

To calculate efficiency first thing you do is determine how much extract you got. Take the volume of the wort you produced corrected to room temperature and multiply by 0.998203 time the SG of the wort (at room temperature). That's the mass of your wort. Convert the SG to °P and divide by 100. That is the fraction of the wort mass that is extract. Multiply by the mass of the wort. You now have the mass of the extract you produced. Divide by the mass of the grain you mashed and multiply by 100. That's the conversion efficiency between grain and extract in the fermenter in %.

If you are a commercial brewer you will approach 80% efficiency. The best a humble home brewer can expect is around 70%. If you do better than that you don't have to be so humble.

 

[Morrey]

Preboil of 1.054 to post boil of 1.060 is well within reason for a normal boil.

Most importantly, what was your volume into fermenter? Even .25 G off has a pretty big impact on your Eff %. Did you make a note of your volume into fermenter?

Putting eff% into a recipe builder helps the recipe determine how much grain you'll need to get to a certain OG or actually the ABV of the final product. If you have 65% eff the recipe may call for 11# of grain. If you tell it 80% eff it may only tell you to use 9.5# of grain which is targeting an ABV goal your for brew. The higher you tell it that your eff% is, the less grain your recipe will call for.

 

[Morrey]

The best a humble home brewer can expect is around 70%. If you do better than that you don't have to be so humble.

Humility is a wonderful thing. But I'd rather be good than humble in this scenario.

 

[str1p3s]

Until you lock in your process and are able to repeat it exactly, your efficiency will change from batch to batch. It will drop with a bigger grain bill too because you need more water to rinse the same % of sugar from more grains. It will also change depending on where you get/crush your grains. I ordered pre-crushed from morebeer.com once and apparently they crush very coarsely and my efficiency suffered for it. I started double crushing at my LHBS and I've hit 80%+ with my last two. It's a guessing game until you get a better feel for what your process will extract from the grains.

 

[TravelingLight]

Most importantly, what was your volume into fermenter? Even .25 G off has a pretty big impact on your Eff %. Did you make a note of your volume into fermenter?

Putting eff% into a recipe builder helps the recipe determine how much grain you'll need to get to a certain OG or actually the ABV of the final product. If you have 65% eff the recipe may call for 11# of grain. If you tell it 80% eff it may only tell you to use 9.5# of grain which is targeting an ABV goal your for brew. The higher you tell it that your eff% is, the less grain your recipe will call for.

Great question, Morrey. I got right at 6 gallons in the fermenter.

 

[pricelessbrewing]

To calculate efficiency first thing you do is determine how much extract you got. Take the volume of the wort you produced corrected to room temperature and multiply by 0.998203 time the SG of the wort (at room temperature). That's the mass of your wort. Convert the SG to °P and divide by 100. That is the fraction of the wort mass that is extract. Multiply by the mass of the wort. You now have the mass of the extract you produced. Divide by the mass of the grain you mashed and multiply by 100. That's the conversion efficiency between grain and extract in the fermenter in %.

If you are a commercial brewer you will approach 80% efficiency. The best a humble home brewer can expect is around 70%. If you do better than that you don't have to be so humble.

Note that this is in kg/liters. For lb/gal multiply by 8.3304 not 0.998203. Also that's not conversion efficiency, that's mash/brewhouse (depending on what wort volume you're using). AJ most definitely knows this, so I shall chalk it up to an early morning typo.

Brewersfriends formula is good for mash (kettle)/brewhouse efficiency (but not conversion), just have to be aware that their grain potentials don't always match up to other software (or malsters). I have a calculator that does each efficiency component as well, and requires you to enter the respective measurements.

https://pricelessbrewing.github.io/BiabCalc/#EfficiencyEvaluation

Note that any inaccuracy in your measurements will result in an equally inaccurate efficiency calculation. Measure your volumes, don't guess at them.

@TravellingLight, efficiency estimation and efficiency measurements are not related. They're two different sets of data.

 

[TravelingLight]

Note that this is in kg/liters. For lb/gal multiply by 8.3304 not 0.998203. Also that's not conversion efficiency, that's mash/brewhouse (depending on what wort volume you're using). AJ most definitely knows this, so I shall chalk it up to an early morning typo.

Brewersfriends formula is good for mash (kettle)/brewhouse efficiency (but not conversion), just have to be aware that their grain potentials don't always match up to other software (or malsters). I have a calculator that does each efficiency component as well, and requires you to enter the respective measurements.

https://pricelessbrewing.github.io/BiabCalc/#EfficiencyEvaluation

Note that any inaccuracy in your measurements will result in an equally inaccurate efficiency calculation. Measure your volumes, don't guess at them.

@TravellingLight, efficiency estimation and efficiency measurements are not related. They're two different sets of data.

Will your calculator you linked work for non-BIAB brewing as well?

 

[pricelessbrewing]

Will your calculator you linked work for non-BIAB brewing as well?

Yes, I haven't gotten around to coming up with a suitable new name but it's fully generalized. Just change the absorption rate to match your equipment (likely 0.12-0.125 gal/lb)

 

[Morrey]

Great question, Morrey. I got right at 6 gallons in the fermenter.

Double check behind me....

6 gallons into fermenter with an OG of 1.060.

I input your grain bill and got 67.54% brewhouse efficiency**. Double check me, but if this is right, you are very consistent with 65% recipe calculations.

I'd much rather be consistent as you are than 50% one brew and 80% the next. Like we read...chase consistency rather than efficiency.

**Although there are several different efficiency calculations, seems most brewers are talking overall Brewhouse Efficiency when they quote numbers.

 

[Sailingeric]

I have been calculating my efficiency pre boil so I know if I need add any "help" to hit my target OG. I have gotten pretty good of nailing my boil off in my kettle and use a strainer to dump the hops over my bucket to drain off the wort so there is very little wort loss. If I come up a little more or a little less in my fermentor that is ok but since I took my reading prior to boil I have an ideal how my efficiency came out and can adjust next time I do a similar beer.