Interesting to read this thread as I've just brewed my first oatmeal stout.
I was copying a recipe that called for rolled oats but ended up with malted oats instead.
As I understand it the difference is they have more potential sugars due to enzymes from malting.
I used 400gm in a 5.15kg grain bill, 7.8%
(equal quantity chocolate malt, 350gm Cara and 4kg Maris Otter. 18L batch, bittered with EKG.)
Been in the barrel a month and conditioning nicely, lovely velvety creaminess.
Interesting article on differences between rolled and malted here
Oats have long been relegated to just supporting roles in a select few beer styles, but the age of oats is upon us. Learn keys to using this brewing grain.
byo.com