Help understanding my Mini Mash SG

[Jesse17]

I'm doing a mini mash kit that uses the below ingredients. Also included in the list is PPPG of each item as I found them listed on a couple sites, and my estimated SG for each addition in a 5 gal. batch...

Specialty Grains:
1 lb. Special B Malt (27 PPPG) = 5.4
4 oz. Debittere Black Malt (22 PPPG ?) = 1.1
2.5 lb. Pale Ale Malt (32 PPPG) = 16
1 lb. Crystal 40 L Malt (29 PPPG) = 5.8
8 oz. Chocolate Malt (24 PPPG) = 2.4

Malt Extracts:
4 oz. Malto Dextrin (40 PPPG) = 2
5 lb. Extra Pale Extract (LME) (36 PPPG) = 36
1 lb Lactose Milk Sugar (40 PPPG) = 8

So, add those up and I figure I should be reading a 1.076 OG but the recipe states an OG of 1.067 and I just realized I didn't even account for the 5 min. additions as listed here:
1 oz. Belgian Cocoa Powder
1 oz. Vqnilla Powder
8 oz. Piloncillo Sugar

Question #1
I'm wondering why my estimate is so much higher than what the recipe estimates? I think most of my PPPG estimates were from howtobrew.com and figured an 85% efficiency, but even if I dropped it down to 80% (including the LME) that would only drop me to 1.072.

Note: I used a PPPG of 40 for the lactose because I found it stated as a mater of fact, anywhere from 30 to 44. So I'm not sure what it really is, but it was only 1 lb. And again, I didn't even include the 5 min additions into my calculations.

Question #2
I added a 1% alcohol boost option to the kit. I would expect that to have added another .0076 to the OG. That would have bumped the kit's estimate of 1.067 up to around 1.073, but my actual read OG at pitching was 1.068 even with the alcohol boost sugar.

The recipe called for a 45 min. mash at 150° F. That's pretty much what I did. I started at 155° and never dropped below 145°. What did I do to get such a lower reading?

 

[cswis86]

Those PPPG estimates are based off of 85% efficiency when in a homebrew application you're likely only getting 75-80%. As far as your OG being low, I think the most likely cause is that you had a greater volume of finished wort which could be due to less evaporation from the boil than you expected or you not accurately measuring sparge/mash water volumes. The recipe OG of 1.067 may be for a 5 gallon batch but if you ended up with 5.25-5.5 gallons you would get a lower OG. I also don't know what temperature the wort was when you took the gravity reading but if your hydrometer is calibrated to 60F and you measured at 70F your OG will likely be a couple points lower. The last thing you can do is get some distilled water, dropped your hydrometer in, and see when it reads. It should read 1.000. If it doesn't you'll need to adjust your wort gravity accordingly.

In reality though 1.068 is perfectly fine and you'll be happy with the results. No sense stressing out over a couple points!