99% Conversion Efficiency??

[copper2hopper]

Ok so I just brewed a 5 gallon Caribou Slobber all grain batch two days ago (actually yielded 5.5 into the fermenter so I'm happy with that. I didn't buy the kit from Northern Brewer I just went to my LHBS and got exactly what I needed.

http://www.northernbrewer.com/documentation/allgrain/AG-CaribouSlobber.pdf

There's the grainbill and my setup is BIAB no sparge with a pump recirculating throughout the whole mash time, on the burner, along with me stirring a lot too. I started with 7.5 gallons of strike water and after my 60 minutes at 153 were done I lifted the bag out and squeezed and got a preboil volume of 7. Only lost a half gallon to absorption. Anywho...after that my volumes and numbers don't matter because I'm posting this to question my conversion efficiency. I was astonished to see that I got a preboil gravity of 1.050. After I plugged it into brewersfriend.com brew house efficiency calculator it says I have a conversion efficiency of 99% I kept rechecking it and refreshing the page and sure enough...99%. Any one have this happen? View attachment ImageUploadedByHome Brew1447438371.584249.jpg

 

[LandoLincoln]

No, I haven't had a 99 before, but I do get in the 90's on occasion. The problem with these programs are that they're using a generalized PPG for the various grain types. The grain that you used might have a higher PPG than what the program is estimating for that particular grain, so you're not actually getting 99.27%.

Sometimes the sacks of grain in the homebrew stores do have the potential PPG on the sacks and if you enter that information into the software THEN you could get a more accurate number, but...not a lot of people buy specialty grains by the sack.

 

[wi_brewer]

Shouldn't your wort volume be 5.5 gallons and not 7.5?

 

[FuzzeWuzze]

How was it measured? Using a refractometer or a hydrometer? I'd think your measurement device was off somehow, i dont think its technically possible to get 99% efficiency at our level..i know some big breweries do but they use mechanical pressure and air bladders to squeeze the living crap out of their grain.

 

[bknifefight]

Shouldn't your wort volume be 5.5 gallons and not 7.5?

Yeah, it looks like you have your pre-boil(?) volume in there by mistake.

 

[bob1852]

Shouldn't your wort volume be 5.5 gallons and not 7.5?

Yeah, it looks like you have your pre-boil(?) volume in there by mistake.

He's calculating conversion efficiency (not brewhouse efficiency), so he's correctly using mash water volume.

Conversion efficiencies in the high 90s are entirely possible and fairly common, but as LandoLincoln says, the actual grain used may be a different PPG than that of the calculator...


Here's a very good read on conversion, lauter, and brewhouse efficiencies...

http://braukaiser.com/wiki/index.php?title=Understanding_Efficiency

 

[BowAholic]

Ok so I just brewed a 5 gallon Caribou Slobber all grain batch two days ago (actually yielded 5.5 into the fermenter so I'm happy with that. I didn't buy the kit from Northern Brewer I just went to my LHBS and got exactly what I needed.

http://www.northernbrewer.com/documentation/allgrain/AG-CaribouSlobber.pdf

There's the grainbill and my setup is BIAB no sparge with a pump recirculating throughout the whole mash time, on the burner, along with me stirring a lot too. I started with 7.5 gallons of strike water and after my 60 minutes at 153 were done I lifted the bag out and squeezed and got a preboil volume of 7. Only lost a half gallon to absorption. Anywho...after that my volumes and numbers don't matter because I'm posting this to question my conversion efficiency. I was astonished to see that I got a preboil gravity of 1.050. After I plugged it into brewersfriend.com brew house efficiency calculator it says I have a conversion efficiency of 99% I kept rechecking it and refreshing the page and sure enough...99%. Any one have this happen? View attachment 315630

5.5 gallons of 1.050 is
72.80% ...

 

[copper2hopper]

Thanks guys! And thanks AZIPA.....you are right I am calculating C.E. not B.H.E. So having 7.5 gallons plugged in is correct. FuzzeWuzze, my Refractometer was used for the measuring. It's always been on target and was measuring a dead on 0 with distilled water so I'm good there. My base malt was Rahr pale 2-row. Not sure what the PPG is for that but it's Canadian so that's why I went with the Canadian pale 2-row default option.

 

[copper2hopper]

Bow...

View attachment ImageUploadedByHome Brew1447441699.289990.jpg

 

[copper2hopper]

Also, my squeeze method is this

View attachment ImageUploadedByHome Brew1447441925.186731.jpg

Pretty darn efficient.

 

[ZebulonBrewer]

Bow...

View attachment 315638

You said you mashed with 7.5 gallons of water, and had 7 gallons pre-boil. The number you'd want for your volume is 7 gallons.

I dig that squeezing method, though.

 

[copper2hopper]

For preboil efficiency yes but not conversion efficiency. Conversion efficiency would be 7.5.

 

[doug293cz]

Your pre-boil gravity of 1.050 seems implausibly high. Your mash thickness is 4 * 7.5 / 10.625 = 2.82 qt/lb. According to Kai Troester's table here, the maximum possible SG at that mash thickness is about 1.0465.

Some things that could account for the discrepancy are:

• Error measuring SG
• Water volumes lower than thought
• Your grain had a dry basis extract potential of 87.2% vs. typical base malts of 80%

Brew on

 

[pricelessbrewing]

Good points have been pointed out already. One more thing is that 7 5 gallons at 155F is actually like 7.33G so that should bring it down to 96.5-97%.

 

[EJay]

For preboil efficiency yes but not conversion efficiency. Conversion efficiency would be 7.5.

But since he can't recover the absorbed half gallon, do you still count it?

If so, my efficiencies are vastly higher than I thought.

 

[pricelessbrewing]

Conversion efficiency you input the gravity and volume of first runnings. Volume should be the volume of work at room temp, so record the temperature as well and calculate the volume once chilled.

 

[doug293cz]

Conversion efficiency you input the gravity and volume of first runnings. Volume should be the volume of work at room temp, so record the temperature as well and calculate the volume once chilled.

SG and volume of first runnings gives you mash efficiency (product of conversion efficiency and lauter efficiency.) Volume of first runnings is unrelated to conversion efficiency, and doesn't figure into the calculation of it. To calculate conversion efficiency you have to use your grain bill weights, grain potentials, and strike water volume to calculate the maximum possible weight percent of sugar in the initial wort, and convert that to maximum possible SG. Then the conversion efficiency is

100% * (Measured SG - 1) / (Maximum SG - 1)​

Kai Troester has precomputed the maximum possible SG's and put them in a table that I linked to in my previous post.

Brew on

 

[pricelessbrewing]

SG and volume of first runnings gives you mash efficiency (product of conversion efficiency and lauter efficiency.) Volume of first runnings is unrelated to conversion efficiency, and doesn't figure into the calculation of it. To calculate conversion efficiency you have to use your grain bill weights, grain potentials, and strike water volume to calculate the maximum possible weight percent of sugar in the initial wort, and convert that to maximum possible SG. Then the conversion efficiency is

100% * (Measured SG - 1) / (Maximum SG - 1)​

Kai Troester has precomputed the maximum possible SG's and put them in a table that I linked to in my previous post.

Brew on

thanks. good catch, I'm sleepy and shouldn't be talking about math right now.