Milk Stout and OG

[Biergarden]

Well, I made a goof.
I brewed a milk stout with an OG of 1.060 made with 8% rolled oats. I goofed because I took the OG before I added 8% lactose to the whirlpool and didn't check the gravity after that.
The wort was transferred over to the fermenter and fermented with 34/70.
Post 5 days of fermentation, the gravity is 1.030. To be sure there is still fermentation going on even with the temperature of the fermenter at 56f, although it's just a very fine trickle of bubbles.
So, does any of the collective have an educated opinion on what the OG might have been after the addition of the lactose? #facepalm

 

[McKnuckle]

How many lbs of lactose were mixed into what volume of beer (measured in the kettle)? From there you can deduce the OG.

One lb of lactose in one gallon of liquid will introduce between 35 and 41 gravity points, depending on the reference. You could also test it yourself using a small amount weighed into a hydrometer sample, and extrapolate from there.

 

[Biergarden]

Thanks for getting back to me on that. That seems like a large spread of gravity. I mean between 35 and 41 points.
I had added 50 pounds of lactose into 210 gallons of wort.
Honestly, I can feel the alcohol just off the hydrometer flask and it has a nice flavor and loads of mouth feel. So, I think it will mature and be ready for St. Patrick's Day. But not checking the gravity post the lactose addition was a bad mistake

 

[McKnuckle]

Between 8.3 and 9.7 points in your particular case. So not a tremendous range. Again, test the specific product you used by dissolving 1 oz weight into a cup of water, and test the gravity of that.