Dilution?

I brewed a parti-gyle 3 weeks ago and ended up way high on the 1st beer's gravity. I was shooting for 1.090, but hit 1.141 (5 gallon batch). I was fine on the second beer at 1.045 (10 gallons).

Anyway, the big beer's been fermenting for 3 weeks and is currently at 1.069. I'm concerned that the WLP028 I pitched isn't going to survive in the high alcohol environment and won't fully attenuate.

I'm thinking about boiling some water and diluting the beer to bring the gravity down so the yeast can finish the job.

My question is in that math. The way I look at it is I'd like to figure out what my current gravity would be it I'd started at the correct 1.090. If I can calculate that then I can dilute to that number.

Also, how will this effect IBUs?

Should I dilute with a hop tea?

Thanks for any suggestions.

Is it as simple as... a 51.1% attenuation from 1.141 is 1.069, and a 51.1% attenuation from 1.090 is 1.044?

That's 57% higher than anticipated. Wow! How did you end up with such a high gravity?

You'll need to add the same amount of water now as if you were diluting it before pitching. That's 2.8 gallons. The IBUs will be diluted as well. If you want the same balance then you will need to add some hops. You might consider dry hoping.

WLP0028 has Medium-High alcohol tolerance which is 8-12%. About 1 gallon of water will drop you from an OG of 1.141 to 1.118 which should be reasonable.

Cool, I came up with 2.8 gallons as well.

I'm not sure how I over shot OG so drastically. This was my first parti-gyle and I'm pretty sure I over thought it - as I have a tendency to do.

It was 32 lbs of Pilsner, 5 lbs of rye and 3 lbs of dark candi. I hit my numbers for the 2nd beer, so I'm not sure where my math went wrong.

I think I'll boil just over 3 gallons and hop it like a regular boil, cool it and dilute the beer. I'd really like to end up with the Fred clone I was trying to make.

Thanks!

I think the real question is did you pitch enough yeast? Whether it's diluted or not, you have 141 x 5gal = 705 gravity points which means you need about 450 billion yeast cells to appropriate ferment that batch. What did you pitch? If it wasn't enough then I'd consider quickly putting in some extra yeast.

I use an under-attenuative English strain in most of my beers and when I brew high gravity stuff I usually add some rehydrated US-05 when the gravity is about half attenuated. This helps dry it out a bit more. Getting some dry yeast in your beer would probably be helpful.

I pitched a 2L starter from a stir plate.