Stout with Lactose

Ingredients
1

Question… does the addition of lactose cause a higher final gravity?  Lactose is fermentable?  It’s not a type of dextrin that can’t be digested by yeast, correct?  I made a milk stout with an OG of 1.055.  Currently (after 10 days) it is 1.017.  I’m using WLP 006… the Bedford Ale Yeast.  I would’ve thought that I would’ve gotten down to 1.010 at least.  Any thoughts?

2

Still contributes to gravity. Not fermentable.

Hey the 1.017 sounds fine. Don’t worry.

3

Yeah, what euge said.  Adds to gravity, not fermentable.  It’s a disaccharide, a sugar, but yeast don’t have the right enzyme to break the bond between the galactose and glucose.  Depending on your recipe, 1.017 is totally reasonable.

4

Thanks guys.  I’m getting ready to add about 30 ounces of cherries soaked in Woodford Select Bourbon into the beer when I keg it.  Do you think that will lower the gravity?  Will I need to add 1/3 cup corn sugar for priming?

5

That’s why lactose is added to a milk stout - to leave some sweetness behind.

Milk stout was patented by Mackeson in 1907 as part of a trend towards sweeter beers, cf Manns Brown Ale invented in 1902.

These days in England a milk stout will have an OG less than 1.040, but an FG above 1.010.

Ant Hayes
Tonbridge, Kent

6

I wouldn’t do it that way.  I’d add the bourbon soaked cherries to secondary, and keg after a few weeks when the flavor has been melded. then keg with normal amounts of sugar, or just force carbonate it.  Don;t worry about the gravity per se.

7

When is lactose normally added?  If it can be added a bottling, it could be an interesting experiment in just how much to add.  That is, bottle a few, add some lactose, bottle a few more, add more lactose, etc. etc.

8

I added my lactose at the final 15 minutes of the boil.  I wonder how many gravity points a half pound made to a final wort volume of 6 gallons?  The beer has a nice chocolately taste thus far after 10 days.

9

I prefer to add to the boil, from an infection point of view. I once had a lactic infection which I think came from adding lactose to the bottle (but I could be wrong).

Ant Hayes
Tonbridge, Kent