Brewhouse Efficiency

[oasisbliss]

I just completed a Pumpkin Ale and I have some questions on my Eff.
My Mash eff is 75.9 % and my BrewHouse eff is 92.5% how is this possible to have my BH be higher than my Mash? want to make sure I am entering everything as needed in BS. see pictures below - thanks

 

[oasisbliss]

Any Input on this? I am stumped on this one.

 

[dyqik]

I think something odd has happened between your pre-boil and post-boil volumes or gravities. I'm calculating the gravity points at pre-boil and post-boil and seeing a big increase.

Est. Pre-boil gravity points: 7.24 gal * 35 = 253 grav points, estimated on 72% efficiency
Measured Pre-boil gravity points: 7.0 gal * 38 = 266 grav points (implies 75.6% mash efficiency by comparison with above)
Est. Post-boil gravity points: 6.00 gal * 50 = 300 grav points, this seems odd - what's the boil off rate you have entered?
Measure Post-boil gravity points: 6.00 gal * 54 = 324 grav points, higher than estimate because gravity is high.

Does this recipe have a malt extract, sugar or other fermentable addition in the boil? That would explain the increase in gravity points during the boil, and the high brewhouse efficiency number, if they weren't included in the grain bill. Otherwise, failing to take the contraction of the post-boil volume on chilling into account could maybe cause it.

ETA: Is this using the recipe here? https://www.homebrewtalk.com/f76/punkin-ale-145060/
That has 1lb of sugar in the boil, so the mash efficiency isn't the only thing determining the final gravity points.

 

[oasisbliss]

Thanks dyqik for answering, The only thing i added to the boil was 60oz of pumpkin and 3/4 lb of brown sugar but that was not added to the design in BS. My boil off rate is 1 gal per hour.

 

[dyqik]

The 3/4 lb of sugar would be the main culprit then! Brown sugar has gravity potential of 1.046/gallon/pound - meaning that adding 3/4 lb to 6 gallons of wort would up the gravity by 5.75 points, adding 36 gravity points to the batch. Pumpkin has a fair amount of sugar and other soluble compounds too, so could make up the rest of the missing 58-65 gravity points (depending on efficiency from kettle to fermenter and chilling contraction - your numbers above suggest 100% efficiency for that assuming you did a 1 hour boil).

 

[oasisbliss]

Got it ! - thanks so much - anyway to adjust for this in BS? so nice to have helpful people like you.

 

[dyqik]

You can add the brown sugar directly in BS - it's in the grain ingredients. For pumpkin you'd have find out the fermentability and yield for your chosen preparation and addition method and add a new ingredient to BS.

 

[oasisbliss]

okay thanks again !