Making an all grain barleywine, and I need someone to check my math (and tell me if we are crazy).
We made some wort with og of 1.096, and got it into the fermentor. On advice from our LHBS, we are going to wait till primary fermentation slows a bit and then add more sugar to get it going again. We plan on doing this somewhere between 2 and 4 times. The idea being that it will help prevent osmotic shock, and we should be able to get the attenuation we are looking for. (in our previous barleywine the yeast just stopped working at around 10% ABV, like 1.040 FG.)
So I would like to bump up the effective OG to about 1.110. By my calculations, we have 5.25 gallons of wort at 1.096, so 504 gravity units. we will add about 0.5 gallons of liquid, and want 5.75 gallons at 1.110. So we need 128.5 gravity units in the half gallon we add. We are using golden promise, so if we mash 5 lb at 70% efficiency, using the assumption of 37ppg, that means we should get 129.5 gravity units in our wort. Then we can just boil the crap out of it till we get it down to half a gallon. Split it 4 ways and save them in the fridge/freezer till fermentation slows down.
We think this will give us the OG we want, and some interesting kettle caramelizeation flavors. We will also be oak aging with a hint of bourbon. (soaking the cubes, but not directly adding bourbon)
So, first, is my math correct, and second, are we crazy?