Partigyle - Big Stinky & Little Stinky

[PSUBrew]

I am planning my first partigyle attempt, and am going to try the recipe in Radical Brewing by Randy Mosher (2.5 gal of barleywine at 1.090 with the first runnings, 5 gal of bitter with the 2nd runnings). I think that I have a handle on the math: Essentially I will be making a 7.5 gallon batch of 1.060 (post-boil target) wort.

However, plugging the recipe into the brewersfriend calculator it seems like there needs to be more fermentables in the grain bill. Using the grain bill in the book at 70% efficiency only produces a 1.039 wort for the overall volume, not the 1.060 needed to reach the gravities for each batch. Here is the grain bill from the recipe (p. 201):

7.5# Maris otter
1.5# Biscuit
1.5# Aromatic
1# Dark Crystal

Am I missing something or do I need to increase the grain bill to hit the gravities based on my system efficiency?

 

[DPBISME]

Have you seen this and the associated charts?

http://morebeer.com/brewingtechniques/library/backissues/issue2.2/mosher.html

It is my reference and written by RM...

DPB

 

[PSUBrew]

I've read the article and I still think I have a handle on what is going gravity-wise with the split batch. My question was specific to the recipe in his Radical Brewing book...I can't make his recipe work mathematically.

 

[clarksc4]

Yes, that grain bill is not enough to achieve 7.5 gallons of post boil 1.060. With 10.5# grains at around 28 points/lb at 70% efficiency, that's less than 300 gravity points. For 7.5gal @ 1.060 you need 450 gp, or about 15# of grains. Hope this helps