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Milk Stout & Lactose


Oct 2, 2019
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Good afternoon,

I have scaled up a recipe for milk stout from 5 gal to 1.5 bbl. This will be my first venture into working with lactose. When I scaled the original recipe up lactose went from 1lb to 9.61 lb. I suspect the original recipe was heavy on lactose but at 9.61 lb in 1.5 bbl I suspect I am pushing the limits.

Has anyone brewed a milk stout? If so what level of lactose worked for you? Is it possible to overdo lactose in a stout?


I find that 5 to 8% is the right range for my preferences. I'd say that over 10% and lactose gets obvious and a bit cloying.

For me, the effect of lactose (sweetness and creaminess) is amplified or limited by the proteins and dextrine left in the beer. Clearly, dextrine will add sweetness of its own, which may not be what you want. I find that a little bit of oats adds the right amount of silkiness to amplify a modest amount of lactose.

Yeast can ferment lactose, but it's a very slow process. it only matters if you're trying to store the beer for while (several months) or use a high amount.
Thanks for the feedback. According to the software I am at 8.4% of fermentables. If I back it off to 7 lb I am at 6.32%. I am using 2 lb of oats as well so mouth feel should be fairly creamy.

The nice thing about working in a winery is if a brew doesn't turn out as expected our cellar guys will drink it!

FYI, one of the questions on my oenology final was What is the #1 ingredient in making wine: Answer: BEER!
dtapke said:
Not Must?

It was a trick question. Must is obviously important for making wine. But a happy wine maker and cellar crew is critical. That?s where the beer comes in. ;)