Oatmeal Stout - Efficiency Issue

[Mikey C]

Hey team

I've brewed an oatmeal stout twice now, and each time my OG is way below what I'm expecting. Each time my OG is out by the gravity contribution I'd expect from the rolled oats. It's like I'm getting no gravity contribution at all from the oats. As a result my oatmeal stout is a bit thin.

Here are the details:

 - I create my recipes in Beer Smith. I haven't had trouble with targets using all malt mashes so I suspect my efficiency profile n Beer Smith is accurate.

 - I use Harraway Rolled Oats as the gravity contribution profile is in Beer Smith along with the Gladfield malt profiles

 - I do a protein rest before the sac rest (probably unrelated but it's part of my process)

 - I use a Grainfather

 - I run the oats through the mill. I have read I don't need to as but I do anyway. In fairness, it doesn't really alter the oats much anyway.

I suspect the Beer Smith profile is incorrect. I could adjust for that next time I brew it, but I'm wondering if there is something else I'm missing. Do I need to do something to the oats before adding them to the mash? I've read you can just add rolled oats to the mash, but it this correct?

Has anyone out there got any ideas?

Cheers

[Crusader-Rob]

Rolled Oats? Use flaked you'll be better off, as with rolled its suggested to to a cereal mash with them... ( google it)
it gelatinises the starches, so you can convert it.

if you use flaked oats, you dont have to bother with that at all. just chuck em in (flaked oats fro mteh super market work a treat)

[Grant R Baker]

How long do you mash for and at what temp?

From memory the rolled oats need to to kinda gelatinize into a glue (that why I put them on top o fthe mash and don't stir them in) which takes time and temp... like 68C.

[Mikey C]

Thanks Rob and Grant.

Rob - I did some research on this was under the impression that flaked and rolled oats were essentially the same thing and didn't need a cereal mash. I'll have a look for flaked oats when I'm next in the supermarket and give them a crack. 

Grant - I mashed at 68C for 60mins. I added the oats first and did a protein rest at 50C while I milled the other grains. I used 10% rolled oats. I'll add the oats last next time and see what happens.

I love oatmeal stout but not getting the body or silky mouthfeel in my versions so far.

Cheers for your help.

[Crusader-Rob]

They are similar yes, but rolled are still slightly different, cereal mashing is the way to go.

flaked oats are pre-gelatinized so can be thrown straight into the mash (they call them quick oats in the US)

I used the home-brand quick oats ofr flaked oats ( i cant remember the actual name) from countdown and they worked great!

[Crusader-Rob]

another question i had, was your efficiency took a hit, i just wanted to check  what your preboil OG was, and if you had any excess of water or anything out of the ordinary?

[Mikey C]

Great, I'll look out for those oats.
Going though my notes, looks like I didn't measure pre-boil OG in this batch. If I had I might have been able to add some dextrose to the boil to get the gravity up a bit. Lesson learned - measure pre-boil OG ... I was 13 points out on the last batch though. Recipe had OG as 1.072. I hit 1.059. 18% oats in that recipe.

[Kevin Sharp]

I'm a bit late to the party ... again, but your problem is the protein rest. Don't do it. It's also acting as a beta-glucan rest. That is destroying the very thing that you want to extract from the oats. There's really no reason to do a protein rest with modern modified malts. Why is part of your process?

[Mikey C]

Thanks Kevin. It's been so long since I have brewed this I forget the rest for the protein rest. It's nearly stout time again so I'll ditch the protein rest next time I brew it. Appreciate the advice.

[Peter Smith]

this is good reading  -  https://www.love2brew.com/Articles.asp?ID=496

http://www.themadfermentationist.com/2012/04/adding-oats-to-boil-co...

he decides this is not actually smart but then goes on with 2 other attempts .. 

[Mikey C]

Bit of a follow-up to this thread if anyone is interested.

I rebrewed the chocolate oatmeal stout a few weeks ago. 12% oats (flaked oats from Countdown - thanks for the tip Rob) and no protein rest (cheers Kevin) and hit my OG on the nose! Mashed at 68C. Good smooth mouthfeel from the oats and nice full body too. Still got a ways to go but it's looking promising.

Thanks for the input chaps.

[Crusader-Rob]

No worries, i take beer as payment for my services.....