SG, OG Efficiency problem

[Sherpa FE]

OK, I was brewing a Hefe-Weizen today, I plugged my ingredients into Beer Smith, and it gives me (assuming 75% Eff) a pre-boil gravity of 1.055. I mash in at 166, and old 154 for 60 min. Mash out @ 168. Drain the Mash Tun, and batch sparge with 170 water. Giving me a total of around 6.8 gallons. I put it into the keggle, and stir both runnings together. I take a Hydro sample AND a refractometer reading. I come up with 11.2 brix, or 1.044. Giving me a grand total of 56% efficiency.

After the boil I take another hydro reading and to my surprise, its 1.061, right on target @ 74% Eff.
So what gives, what am I missing, am I doing something wrong, or is pre-boil hydro samples just a waste of time, If so then why did I get a refractometer??

Thanks for the help.
Josh

 

[Beerrific]

Did the refractometer and the hydrometer give you the same gravity reading?

Did you correct for temperature?

Post the recipe.

 

[Sherpa FE]

Yes They both read the same thing, un fermented wort was cooled to 60 degrees so no temp correction needed.
Recipe posted below.

Type: All Grain
Date: 3/1/2008
Batch Size: 5.00 gal
Brewer: Josh
Boil Size: 7.00 gal
Boil Time: 75 min Equipment: Josh's 5 - 10 Gallon Brew Equipment
Brewhouse Efficiency: 75.00

Ingredients:

5.60 lb Pilsner (2 Row) Ger (2.0 SRM) Grain 50.45 %
4.40 lb Wheat Malt, Ger (2.0 SRM) Grain 39.64 %
1.10 lb Munich Malt (9.0 SRM) Grain 9.91 %
0.75 oz Hallertauer [4.80 %] (60 min) Hops 12.2 IBU
0.75 oz Hallertauer [4.80 %] (5 min) Hops 2.4 IBU
1.00 items Whirlfloc Tablet (Boil 15.0 min) Misc
1 Pkgs Bavarian Wheat Yeast (Wyeast Labs #3056) Yeast-Wheat

Est Original Gravity: 1.060 SG
Measured Original Gravity: 1.061 SG
Est Final Gravity: 1.014 SG

Estimated Alcohol by Vol: 5.99 %
Bitterness: 14.7 IBU Calories: 273 cal/pint
Est Color: 5.1 SRM Color: Color
Mash Profile
Mash Name: Single Infusion, Medium Body Total Grain Weight: 11.10 lb
Sparge Water: 3.72 gal Grain Temperature: 72.0 F
Sparge Temperature: 168.0 F TunTemperature: 72.0 F
Adjust Temp for Equipment: FALSE Mash PH: 5.4 PH

Single Infusion, Medium Body Step Time Name Description Step Temp
60 min Mash In Add 13.88 qt of water at 165.9 F 154.0 F
10 min Mash Out Add 7.77 qt of water at 196.6 F 168.0 F

 

[Denny's Evil Concoctions]

uhm preboil has more water. Post boil is your final SG other wise known as OG.

You can use a refractometer for the OG and arguably the FG with the right software and calibration.

Preboil is useful for determining some things to do with your system. Don't have the time to explain right now.

 

[Bobby_M]

Ok, admittedly, I haven't used Beersmith in a long time but plugging the numbers in to BTP, it's saying 76% brewhouse would give you 1.060 OG at 5 finished gallons. If I make it so the preboil kettle volume is 6.8 gallons, it says that gravity would be 1.044. Exactly what you found huh? The thing is, whatever gravity you entered into BS, it seems the program though you meant post boil. Someone a little more familiar will be able to tell you where you should enter your actual preboil grav/volume.

 

[ajf]

I was going to suggest that you didn't stir enough, but if you boiled 6.8g down to 5.0g, the 1.044 pre-boil would increase to 1.060 post boil.
I guess you probably entered an incorrect volume somewhere.
I'd switch from Beer Smith to Pro Mash, because when I do the same thing, I tend to get efficiencies > 100%

-a.

 

[Sherpa FE]

Could have entered a volume somewhere wrong, but I do not think I will buy another program.
There is a friend coming over today, he has the Beer Smith program, so I'll have him take a look at it and see what I am doing wrong.

I do lose a lot in the boil for some reason, so I am going to have to make adjustments accordingly.

 

[Reverend JC]

Yes, your OG will seem lower due to the amount of water that is in the solution and making the wort read "thin".

There are spreadsheets out there that can show you when your evaporation rate is plugged in a graph of where your beer will be during the boil. for example, you start out with 6.8, it will show you what your gravity should be at 5.8 with your evap rate, and again at 5.

Remember when taking your OG what you are doing is using that with your evap rate to calculate your Final Gravity.

As far as i know, your eff can only be determined once the boil is done, or atleast that is when i figure mine out.

 

[Sherpa FE]

Yes, your OG will seem lower due to the amount of water that is in the solution and making the wort read "thin".

Now that makes sense, same amount of sugars but in 6.8 gallons in my case being brewed DOWN to 5 gallons, at the same amount of sugars.

So why do people like the refractometer so much?? Is there a step in calculating pre-boil Efficiency that I am missing??