Hi all,

I'm trying to formulate a partigyle batch for this weekend. I'm planning on making a double IPA and a Pale. I've never done a partigyle, so I consulted the web to try to find out how to do the calcs, but have come up with some conflicting info (I think).

I plan to batch sparge 50/50. I want the double to come in around 1.070.

According to (2) and (4) below, I want to start with a recipe that would give me 1.060.

According to (3) below, I want to start with 1.0530. (1) basically agrees with (3).

So, which one is it? Thanks!

(1)

"Roughly speaking, the second batch will have half the gravity of the first batch. "

http://www.homebrewtalk.com/wiki/index.php/Parti-gyle
(2)

Batches split into two equal volumes have a different ratio: ~58% of the extract will be in the first half of the runoff and ~42% in the second half. For example, a 15-gal master batch designed to produce 16 °P wort contains 240 °gals (15 X 16 = 240). The first half will be 18.56 °P (240 X 0.58/7.5 =18.56); the second half will be 13.44 °P (240 X 0.42/7.5 = 13.44).

http://morebeer.com/brewingtechnique.../mosher.html#3
(3)

1.060 total -- 1.080 (first half), 1.040 (second half)

http://morebeer.com/brewingtechnique...shertable.html
(4)

For a 50-50 split by volume, with half of the wort in each batch we get a roughly 58% of the gravity points in the first batch. So a 1.060 overall batch OG would translate to a 1.070 first runnings and 1.050 second runnings, with both of equal size.

http://beersmith.com/blog/2011/10/07...from-one-mash/