Partigyle Ideas for IPA and Bitter

I couldn't decide if I wanted to do a special bitter or APA for my next brew, then I had a revelation--do both at once!

The plan: 5 gallons (double my normal batch size) of 1.051 wort (mashing about 153, I think), splitting it in half, then taking about 1/4 of each running and mixing it with the other. According to my calculations (and this chart), this should put me around 1.06 for the first runnings and 1.043 for the second runnings(which will then be fortified with some extra crystal malt). I plan to hop the first to about 55 IBUs with Cascade and Summit for an milder American IPA, and use Northern Brewer and Williamette on the second for something like a Special Bitter with a ratio of ~.7 BU:GU. Both will get S-04 yeast. I plan on using the grain bill from yeoman special bitter, but only adding the crystal 120 to the small beer. The IPA should be similar to this IPA I brewed already and liked, but with darker crystal and toasted instead of Vienna.

My other thought was to do something like mixing all the runnings, mashing a little high, using 1/2 lb sugar to get half up to 1.06 and dry out the IPA, and diluting the other half to get down to 1.045ish, then hopping as above.

Does this sound good? Any thoughts/suggestions?

Download this parti-gyle simulator and run your numbers.. I've used it a lot and come up with almost exact numbers it said..
http://www.braukaiser.com/wiki/index.php?title=Batch_Sparge_and_Party_Gyle_Simulator

I forgot I had downloaded that sheet. I plugged my numbers in, and it looks like I should mix closer to 1/3 of each running with the other (instead of 1/4) to get the gravities I desire. This is the reason I was thinking about simplifying and just mashing one batch, bumping one gravity with cane sugar, and diluting the other to get a bit more volume (and adjusting hops accordingly), I would be less dependent on the calculators.

Nothing risked, nothing gained, though, so I'll take your word for it and hold you accountable if it comes out poorly!

I've done a similar thing, except that I added some more base malt to the MLT on the second running--I was making an English IPA/ESB combo, so mine was MO + some crystal 60, but it's essentially what you're thinking of. Turned out great. And I used the same Partigyle calculator that edmanster recommended. Next time I'm planning to make that combo again I'll definitely repeat.

I recently tried this technique but on different styles of beer. If you do not happen to have accurate records of previous beers made with a similar grist and mash, I'd opt to use your second method (add sugar to one half, dilute the other) to get through the day without having to fly on the seat of your pants in swapping portions of each beer to obtain the right gravities, etc.

On the other hand, I did a no-sparge and split my only runnings between two kettles - 1 kettle got the first 4 gallons, the other got the remaining 4. The gravities weren't equal, they were 10-12 points different. And I also recommend using that spreadsheet!

I am brewing now. I mixed back and forth a bit after alternating between two collection vessels at each stage of the sparge/run-off. I diluted with a half-gallon of water to get better hop utilization, and will dilute more after the boil if necessary. I'll boil the IPA next.

Brewday done! [except clean-up ] I hit better efficiency than I had planned (85% instead of 80%), but I decided to round the hops up a little before I boiled the bitter, and I was able to adjust the overall volume and hop additions of the IPA pre-boil, so I kept the same BU:GU ratio. I aded a quarter gallon to each recipe, so there should be a couple extra bottles of each which should come in handy next semester when I'll be too busy to brew. I did it!