This recipe is based on Avery's, discontinued, Mephistopheles. However, Mephistopheles lies in wait, within his soulstone. For this beer contains the soul of Mephistopheles. Black as the soul of the demon lord. While this soulstone exists, Mephistopheles cannot be destroyed.
https://blog.averybrewing.com/mephistopheles-homebrew-38068c7e53c0
Recipe modified for my system and my process.
Add extract and simple sugar at 60 min mark on the boil.
Note: need to look up yeast nutrient additions for big beers. I have fermaid o in stock at home. May need to copy other big beer oxygenation schedules to get the yeast to eat enough sugar.
Aerate with pure O2 for 120 seconds at 1 L/min to target roughly 14 ppm dissolved O2.
Aerate again at 12 hours for 70 seconds at 1 L/min to target an additional 9 ppm. (recommended in Yeast book, page 84)
Target 40M cells per mL per yeast book's instructions on pitching high gravity beers. A 7 liter starter (constant stir) at 1.036 gravity with 100 B cells will result in approx 1107 B cells.
Start fermentation at 66°F ramp to 77°F @ 1.074 specific gravity. According to the Avery blog, it usually takes about 48 hours to reach 1.074
Age on bourbon soaked oak cubes until desired oakiness is reached. Drain bourbon before adding cubes to beer. It's extremely easy to overdo the bourbon flavor. You can always dose bourbon at the end if you want more bourbon flavor.
Consider adding vanilla, coffee, cocoa, coconut, or other great stout additions. I don't think peppers would work with the belgian yeast flavors.
If you aren’t able to get that much sugar out of the mash you may boil for longer and/or add a 50/50 mix of DME and Dextrose Corn Sugar to the boil to hit your OG target.
Original recipe uses wyeast 3787