First AG Batch and my efficiency at 90%?

[fu_gazi]

Did my first AG batch today (saison) and all went well. I hit all my temps. Overall it went really well. I used a few online calculators along the way, and at the end I entered my information into the brewhouse.com efficiency calc and it reported an efficiency of 90.9%.

Pre boil grav 1.031
Post Boil grav 1.071

I just don't feel like that is right. Any thoughts?

 

[PastorofMuppets]

please post recipe. Sounds way odd to have pre and post boil gravity so far apart.

 

[MedicMang]

Did you measure the gravity at a high temp? That throws off hydrometers.

That does not seem right. Boil off doesn't add THAT many gravity points.

 

[fu_gazi]

The gravity values are corrected for 70*.

I used this recipe:

10 lbs Weyermann Pilsner
2 lbs Weyermann Light Wheat
1 lbs Belgian Light Candi Sugar
.5 lbs Weyermann Vienna

7 aau Warrior (Bittering)
.5 oz Kent Goldings (Flavor)
.5 Bitter Orange Peel (Flavor)
.25 oz Kent Goldings (Aroma)

Mashed for 60 min @152
Sparged 10 min @ 180

Ended up with 6.5 gallons after both runnings, boiled down to 5 gallon final volume.

 

[BrewWorm]

The gravity values are corrected for 70*.

I used this recipe:

10 lbs Weyermann Pilsner
2 lbs Weyermann Light Wheat
1 lbs Belgian Light Candi Sugar
.5 lbs Weyermann Vienna

7 aau Warrior (Bittering)
.5 oz Kent Goldings (Flavor)
.5 Bitter Orange Peel (Flavor)
.25 oz Kent Goldings (Aroma)

10 lbs pils = 350 pts
2 lbs wheat = 72 pts
1 lbs sugar = 45 pts
.5 Vienna = 17 pts

So you have a 494 pt possible wort. If post boil volume is 5gal then that's a 1.098 possible og. You hit 1.071, that's 72% efficient

 

[blakelyc]

Efficiency is the measurement of sugar extraction vs a theoretical maximum. Efficiency shouldn't change pre- and post- boil because the amount of sugar doesn't change. Boiling removes only concentrates the wort by removing water.

I measure efficiency pre-boil only. Looks like that may yield a more reasonable measurement for you. Assuming your pre-boil gravity is correct, it would appear your boil-off rate was kind of extreme.

-b

 

[fu_gazi]

Assuming your pre-boil gravity is correct, it would appear your boil-off rate was kind of extreme.

Should I have used a smaller pre-boil amount and not boiled as aggressively?

 

[BrewWorm]

Should I have used a smaller pre-boil amount and not boiled as aggressively?

We need to know your pre and post boil volumes to calc correctly

 

[blakelyc]

What were your pre-boil and post-boil volumes? A lot depends on the geometry of your kettle. On mine, I typically boil off just less than 1 gallon/hour.

 

[thadius856]

Efficiency is the measurement of sugar extraction vs a theoretical maximum. Efficiency shouldn't change pre- and post- boil because the amount of sugar doesn't change. Boiling removes only concentrates the wort by removing water.

I measure efficiency pre-boil only. Looks like that may yield a more reasonable measurement for you. Assuming your pre-boil gravity is correct, it would appear your boil-off rate was kind of extreme.

-b

1.5 gallons boiloff is extreme? That's my hourly rate.

 

[fu_gazi]

What were your pre-boil and post-boil volumes? A lot depends on the geometry of your kettle. On mine, I typically boil off just less than 1 gallon/hour.

The brew365 calc indicated a pre-boil volume of 6.37 gallons. It appears I wrote down 6.5 gallons, that could be part of it.

My pre boil was 6.5 gal and my post-boil was 5 gal.

Pot dimensions (Aluminum) - ~14 7/8 in diameter
~ 13 in tall

58,000 btu propane burner

 

[thadius856]

That's a reasonable boiloff rate. I boiloff 1.5 gal/hr in a keggle on a 55k BTU burner running at about 80% flame. Our surface area and burners are similar.

Your pre-boil gravity should have been in the neighborhood of 1.055, assuming the 1.071 OG is correct.

How did you measure pre-boil grav?

 

[fu_gazi]

Took a sample from the runnings out of the mash tun and cooled it. Ended up measuring it at 70*.

I am guessing, looking back now, I should have taken a representative sample from the pot pre boil. Would that have made a significant difference?

 

[thadius856]

Unless you no-sparge or BIAB, the sample you took is very non-representative.

I recommend you take the sample after you dump the last runnings into the kettle, right before you apply flame.

 

[blakelyc]

1.5 gallons boiloff is extreme? That's my hourly rate.

Doh! Didn't even see the volumes above. No, not extreme

 

[fu_gazi]

Unless you no-sparge or BIAB, the sample you took is very non-representative.

I recommend you take the sample after you dump the last runnings into the kettle, right before you apply flame.

Ya. I batch sparged it.

Thanks for the help. I won't make that same mistake again! LOL

 

[thadius856]

It's probably obvious, but I should probably mention just in case it wasn't obvious.

You'll want to stir the kettle briefly before taking that sample.

Best of luck!

 

[fu_gazi]

You know, I was a Geologist for 8 years before I became a Firefighter. You think I would know better!!!!! LOL!