Where are the GUs?

Beer Recipes
1

The October issue of Brew has a recipe on Page 59 that has me confused.

The Neshaminy Creek Brewing Co.s Maximum Porter Clone all grain version has an OG of 1.066.

Using the .65 efficiency standard and the potential extract data on page 4 of the issue for the malts listed, and allowing a very generous 100% efficiency for the 4 oz. of coffee-infused dark chocolate (not sure how to calculate that), I come up with 283 GUs.

Since lactose is not fermentable, I did not add any GUs for the 1.5 lbs of lactose.

But shouldn’t 5 gals at 65% efficiency require about 330 GUs for OG of 1.066?

By my calculation, the OG would be about 1.056.  What am I not understanding?

Thanks for your reply.

2

While lactose is not fermentable by typical yeast, that addition does increase the original gravity. I believe that you should include that addition in the gravity calculation.

3

Just checking my brew notes from a milk stout made last year.  1 Lb of lactose added to 6 gal of wort near the end of the boil increased the OG about 7-8 points.  It also raised the FG by about the same amount.

4

Thanks, but is there any kind of formula to account for the lactose  contribution or do you just see what increase you got from it  after the fact?

Thanks

5

Brewer’s Friend lists lactose at 41 ppg, meaning that a lb. will add about 8 points to a 5 gal. batch.

6

Thanks,

I have my own calculation program in Excel and I will add that in.