98% measured mash efficiency?

[Pintabone]

This is my second all grain batch and first using the Beersmith desktop software. I have to imagine that I calculated something wrong along the way because the efficiency seems way too high.

I brewed a Rye pale ale yesterday using a 10 gallon Igloo cooler as a mash tun with a false bottom. The details are below from Beersmith. Is this possibly accurate or is there something common using the Beersmith software that I'm missing? I adjusted the hydrometer readings based on the temperature of the wort letting them cool closer to 60 degrees.

6 lb Pale Malt
2.5 lb Rye Malt
14 oz Crystal 60
9 oz Vienna
9 oz White Wheat

Target mash temp was 153, I started at 152 and it actually dropped below 150 mid way through. Batch sparged using about 5 gallons sparge water vorlaufing .

Est post mash / pre-boil grav 1.041
Measured post mash / pre-boil grav 1.047
Measured mash eff: 98%

Est original gravity 1.053
Measured OG 1.058
Brewhouse eff: 89.75%

Appreciate any insight!

 

[Dcpcooks]

Have you set up an equipment profile ? Did that data match your liquid levels? Did you hit your volume levels both pre and post boil into the fermentor? All of that impacts efficiency.

 

[Pintabone]

I did set up the equipment profile and was good on the volumes I think.

Est Pre-boil Vol 7.65 gal
Measured pre-boil vol 7.75 gal

Into fermenter
Est batch size 5.5 gal
Measured 5.75 gal

 

[Dcpcooks]

Well then you've got a great set up going!

 

[pricelessbrewing]

98% mash efficiency is basically impossible. I'll call BS. Most likely cause; inaccurate grain or volume measurements.

 

[bajaedition]

98% by whose standard, because you would have to leave the grains in the wort to get 98%

now is that 98% of predicted efficiency? then that is good

 

[bob1852]

If by mash efficiency, you mean conversion efficiency, then yes, 98% is possible...

And 90% brewhouse is common, too.

 

[doug293cz]

With a 10.5 lb grain bill, single batch sparge, and 7.75 gal pre-boil volume, the max theoretical mash efficiency is 89%, which is a conversion efficiency of 100% and lauter efficiency of 89%. Pre-boil gravity would be max 1.043. A higher measured pre-boil SG would likely be due to insufficient mixing of first runnings and sparge wort, which can result in either high or low readings depending on just where the sample is taken.

Brew on

 

[Pintabone]

With a 10.5 lb grain bill, single batch sparge, and 7.75 gal pre-boil volume, the max theoretical mash efficiency is 89%, which is a conversion efficiency of 100% and lauter efficiency of 89%. Pre-boil gravity would be max 1.043. A higher measured pre-boil SG would likely be due to insufficient mixing of first runnings and sparge wort, which can result in either high or low readings depending on just where the sample is taken.

Brew on

I see what you're saying. That makes the most sense to me. I think all the measurements I made were accurate. So do people typically stir up the wort a bit before taking the pre-boil SG to avoid pulling a sample that's skewed by first runnings or sparge? I pulled it from the ball valve on the boil kettle so it makes sense that it could be skewed to measure higher based on the first runnings.

Glad to hear though that the overall brewhouse efficiency could be accurate.

 

[doug293cz]

I see what you're saying. That makes the most sense to me. I think all the measurements I made were accurate. So do people typically stir up the wort a bit before taking the pre-boil SG to avoid pulling a sample that's skewed by first runnings or sparge? I pulled it from the ball valve on the boil kettle so it makes sense that it could be skewed to measure higher based on the first runnings.

Glad to hear though that the overall brewhouse efficiency could be accurate.

It actually takes surprisingly aggressive stirring to really homogenize the wort. Get a good whirlpool going in one direction for about a minute, and then reverse the direction of the whirlpool for another minute. Another option is to let the wort boil for about 1/10th your total boil time and then take a sample. Reduce your pre-boil volume in the efficiency calculation by 1/10 of your total boil off.

I calculate your brewhouse as 5.75 gal * 58 pts/gal / (10.5 lb * 37 pts/lb) = 86%. So, if your grain potentials are a little lower than my assumed 37 ppg, then 89% could be the actual brewhouse eff. A safe assumption is that any efficiency calcs are only accurate to about +/- 4%, or so, due to uncertainties in the grain potentials, moisture content, volume measurement errors, SG measurement errors, etc.

Brew on

 

[Pintabone]

Great. Thanks for the insight. I didn't think 98% post mash was possible so I assumed I was doing something wrong.