Question About Calculating OG For High Gravity

I currently use Beersmith to help with my all grain calculations. But I'm trying a different process with my recent high gravity endeavor. I don't get very good efficiency with my higher gravity brews, but this one came in at 1.111 for a 5 gallon batch. I have it separated into two 6.5 gallon BB's.

I originally used 1 cup of PacMan slurry in about 24 ounces of wort. I made another 2.4L starter with a pound od DME and WLP099. And I plan on adding 2 more pounds of corn sugar during the next few days....and lots of O2 for the next few days as White labs recommends.

What is the best way to calculate the additional fermentables I'm adding so that I have a better idea of the real OG?

I've thought about adding the fermentables and liquid volumes to my calculations, but I'm not sure if that will be accurate.

I'd appreciate any thoughts on this.

If you decant and pitch just the slurry, you won't add much sugar or alcohol... if you oxygenate well, it will prevent much alcohol creation - except through maybe crabtree reaction.

Also Chris White (Yeast) recomends using malt, not sugar for your starter - or same sugar as you want the yeast to ferment in the end. - if you were doing a wine, you're starter would be juice.

Thanks. I appreciate your input.

I think I have enough malt in this barleywine already without adding more. There will be plenty of unfermentables. The corn sugar should raise the alcohol level and ferment out at 100%.

What I'm trying to understand is when adding fermentables during fermentation, be it dextrose or maltose, how or if I need to adjust my calculations to figure out my OG.

Sorry I didn't understand you question.
I'd yank out the algebra and figure it out by the numbers. I've found that the calculated and measured are close but not the same

So if you add a lb of dme then add 45/brew size to the og.

But that is just me

Right so where the algebra comes though. If your brewday OG and volume are 1.060 and 5 gall, then you have 300 points (5 *60) and if you ad .5 gal and 2lb of dme that is 90 more points and .5 gal vol - so now 390/5.5 gal = a calculated og of about 1.071 ... then latter you add another .5 gal and 90 points of dme for 480 and 6 gal or 80 points and 1.080 calc og

Again, that is how I would figure it. If I were adding a small amount of sugars - say 1/4lb and .5 gall, I'd probably figure that my gravity ahsn't changed much, although someone could do the math and show me I'm wrong