Tweaking a stout recipe - adding oats... adjust existing grain amounts?

[fobster]

Hi folks,

So my next brew is a stout and I'm going to use a recipe which got good marks in a competition last year, though feedback said the beer was a bit thin so my plan is to mash at 154 F and add 600g of flaked oats, aiming into oatmeal stout territory. My question is, if the current recipe is...

4.3kg Maris Otter (86.5%)
330g Chocolate malt (6.7%)
220g Roasted Barley (4.5%)
110g Special B (2.3%)

...do I leave those amounts as they are and just add the oats?

Thanks

 

[UndeadFred]

I'd say "sure". Higher temp mash will in theory lower fermentables, and Oatmeal will leave a lot more complex sugars, so probably your not going to change overall ABV much, but if you do, hey, it's a bonus anyway..

Fred

 

[m00ps]

Oats are basically a base malt in my mind. If you dont want the OG to change much I would subtract 600g from the MO

 

[Hoppy_Sanchez]

2 lbs of oats and you won't regret it

 

[Calder]

Oatmeal will leave a lot more complex sugars, so probably your not going to change overall ABV much, but if you do, hey, it's a bonus anyway..

Not sure I agree with this. It is not like Crystal with unfermentable converted sugars already present. You are doing the conversion, so a low mash temp will produce a lot of fermentable sugars just like regular base malt. You do need to add a base malt to provide the enzymes.

2 lbs of oats and you won't regret it

^^^^^ this. Use flaked from the LHBS, or quick rolled oats from the Supermarket.

 

[UndeadFred]

I've only done an Oatmeal stout once. IIRC, I think around 15% of the bill. I did a 90 minute mash and used standard oatmeal from the store and not even quick Oats.

If they didn't fully convert, the rest of the malt had to be from a special perpetual motion machine batch because I got like 84% conversion efficiency on that batch.

I have READ that oatmeal makes a "complex sugar" but I am not sure if I agree either. I would tend to just add it as I never actually mind a slightly higher gravity brew! And that is what I meant. I have no idea if the sugars it produced after conversion were simple or complex. That particular batch was a 1.080 stout and it wasn't boozy at all.. so I just assumed....

Fred

 

[JKaranka]

600g is just over 10%, which is a good starting point. You might want to slightly adjust your bitterness.

 

[Calder]

I've only done an Oatmeal stout once. IIRC, I think around 15% of the bill. I did a 90 minute mash and used standard oatmeal from the store and not even quick Oats.

If they didn't fully convert, the rest of the malt had to be from a special perpetual motion machine batch because I got like 84% conversion efficiency on that batch.

My experience is that any rolled oats will convert fine. I believe the rolling process generates enough heat to gelatenize the starches. But whenever I say that, some people jump in and say that's not the case and it needs to be quick oats. So to be safe, and not have someone saying i'm giving bad advice, I only recommend the quick oats, but I use any rolled oats that are available myself.

 

[Hoppy_Sanchez]

Not sure I agree with this. It is not like Crystal with unfermentable converted sugars already present. You are doing the conversion, so a low mash temp will produce a lot of fermentable sugars just like regular base malt. You do need to add a base malt to provide the enzymes.



^^^^^ this. Use flaked from the LHBS, or quick rolled oats from the Supermarket.

Use flaked oats.