partigyle, getting started

I'm doing a big ass Hoppy Valley Double IPA again soon. Last time I had a lot of sugar left in my mash tun.

I'm thinking this time I would like to use some of that.

Eventually I'd like to work it out so I can run the recipe as a grain-only partigyle, but I need to inch into it, as I'll need a better handle on how to calculate my gravities.

My plan is to take my original recipe for the Hoppy Valley DIPA and add 10-20% more base malt.
I'll do the math to determine how many points will end up in the kettle at boil volume (based on pre-boil gravity), then try and put together a SS (if I have time, if not I'll just use a calculator) to input current volume and current gravity while running off. It will output the total points in kettle. When I hit that number from my target, I will stop runoff and top off with water and get that boil going.

Then I will run off the remainder, tracking the sugars down to 2 degrees plato. I stop at 2 degrees, stir and take a measure of the gravity and volume. I can then calculate an extra-light DME addition to achieve a desired Pale Ale or ESB pre-boil gravity, and water to get to volume.

Having learned how much sugar I can get from the second runnings (I fly sparge) I can adjust upward with my DIPA mash in future batches to introduce more sugars from the mash and work towards an all-grain end result.

Sound reasonable?

My DIPA has a specific recipe and I'm okay with the base malt adjustments, but I need to hit specific volumes and numbers for it. I'm a bit more open with the 2nd batch, as I'm just trying to figure out ways of doing the partigyle for fun (and beer).

Sounds like a plan to me... some thoughts would be you could just drain off 7 gallons or whatever your preboil amount... add some more 2row and maybe a touch more crystal (mash it for a little while) to increase the mouthfeel & gravity. I have to assume you are going to be mashing your IIPA a few degrees lower than you would normally mash an APA and doing this might make up for it a bit.

Here is a really simple calculator that I used when doing my partigyles:

http://www.astrocaver.com/java/Parti-Gyle.html

Can you quantify how much sugar you left behind before? I batch sparge and my numbers run 50%, 33% and 16%, so it is very easy for me to set up a partigyle. I just use half of the first sparge or all of the second.

my pre-boil volume for DIPA is 18.5 gallons. Post boil gravity is 1.090 (this time).

I try to keep everything in 15.5 gallon batches now (everyone gets a carboy).

I think my runoff was at about 8 plato when I stopped the runoff on the last DIPA.

I guess there's no reason why I could not batch sparge it... I'll have to consider the options.

that calculator suggests that with a 50/50 (two 15 gallon batches), for a 1.090/1.045 I would start with a 1.067. That is planning for a 30 gallon batch, right?

Calculating my recipe to that has 78 pounds of grain. I've got a blichmann 20G, so I'm not going to fit that much in it to mash. If I track my runoff down to 2P, I can take a volume measurement on this time through and see what it is. Is it close to a 10g batch? If so I can pull out my keggle, dust it off, and plan on doing the 2nd batch as a 10g in the future. I'll need to plan the first one based on carboys people can take home, but knowing it in the future will mean I can say 3 carboys of DIPA and 2 carboys of ESB, or whatever.