Calculating efficiency makes me mad!!!!

[bandt9299]

Ok so today I brewed a Munich dunkel, its Jamilz recipe. Beersmith says OG should be 1.060, I collect 7.5 gallons ( i think anyways, it was up to the line in the middle of my keggle) gravity was 1.046 right on the money 76% or so efficiency, 5.75 gallons to fermenter gravity reading 1.054, 68% efficiency. I am reading Designing Great beers and according to that, your efficiency shouldn't change from pre boil to post boil. I did the numbers on paper (which was cool to learn) and it had me @ 78 % pre boil and 70% post. What gives????

Im not mad about the efficiency, 0G of 1.054 is closer to style for a Munich Dunkel, I'm just trying to understand my new book as it relates to efficiency.

Thanks

 

[smizak]

Dude, read the thread I started this morning.

https://www.homebrewtalk.com/f36/efficiency-observation-106610/

I think it may help you out.

 

[PhlyanPan]

What were your temps when measuring your gravity?

 

[bandt9299]

The temp on the pre boil reading was 77 degrees (stuck it in the freezer), which I adjusted for, and the post boil was 56 degrees (right out of the shirron). Some have mentioned that hot wort expands, if that was the case my efficiency would be even higher if I really had a little less wort.

 

[Kaiser]

How much wort did you leave behind in the brew kettle after transferring to the fermenter?

Kai

 

[bandt9299]

I have a pump and no hop stopper so I leave nothing in the brew pot, before the pump I use to whirlpool and siphon but I always measured what what left over in the pot and added that to my final numbers, which I'm sure inflated my efficiency.

Is that where you were going with that Kai?

 

[Bob869007]

What is the purpose of checking pre and post boil efficiencies?

 

[Kaiser]

bandt, how do you measure the gravity? Especially, how do you chill your samples if you need to.

Kai

 

[Fatgodzilla]

Dude, read the thread I started this morning.

https://www.homebrewtalk.com/f36/efficiency-observation-106610/

I think it may help you out.

Common sense Smizak. Never thought of it, but then again, I really don't worry about efficiency anyway. I rely on OG when cool and adjust accordingly.

Don't worry that no one seems to have read your thread when answering this thread .. you can lead a llama to water, but they are damn difficult to drown.

 

[eriktlupus]

m guess would be that your preboil volume measurement was off.

 

[bandt9299]

Kai,

The pre boil sample was in a plastic cup, put in the freezer for 20 minutes or so, the post boil sample was right out of the chiller, I checked the temp and adjusted for both.
Today I will mark my spoon @ 1 gallon increments and somehow mark my keggle, so I can be sure about the volume.

Thanks

 

[Bobby_M]

What is the purpose of checking pre and post boil efficiencies?

Preboil efficiency tells you what OG you should expect upon boildown. It allows you to make minute adjustments by either adding DME/LME to bring you up to a desired OG when you fall short or to dilute to bring it down. If you don't like OG adjustments on the fly, you can modify your bittering hop addition to keep the BU:GU ratio where you originally intended.

Checking efficiency into the fermenter is a way of obtaining your average losses between the mash and fermenter so you can better plan in the future. This is also a measurement of the literal "cost" of that volume of beer at that gravity.