Oatmeal Stout Recipe Critique

[CanuckBrwr]

Hey everyone,

I wanted to make an oatmeal stout, and after reading up a bit on the forums it seems that my best bet is to mash the oats rather than just steeping them. This is my first partial mash, so I figured I'd post the recipe on here and see if anyone had any comments or suggestions. (sorry about the odd weights, but I did all of this in kg and then converted before posting here since this seems to be a pretty Imperial place )


Partial Mash (155F mash, 160F sparge):
1.65 lb Canadian - Pale 2-Row 14.1%
1.10 lb Flaked Oats 9.4%
0.55 lb American - Chocolate 4.7%
0.55 lb American - Pale 2-Row - Toasted 4.7%
0.55 lb American - Roasted Barley 4.7%
0.25 lb United Kingdom - Black Patent 2.1%

7.05 lb Liquid Malt Extract - Light 60.3%

Hops:
1 oz Columbus (15.2%) 35 min
0.5 oz Styrian Goldings (5.1%) 35 min

Nottingham ale yeast (1 pkg dry)
Ferment at 20 C (68 F)
Transfer to secondary, and clear with gelatin finings.

IBU: 30
SRM: 33

Please let me know what you think, or if you have any suggestions. I've only been brewing for a few months, so I can use all the help I can get. Thanks a bunch!

 

[CanuckBrwr]

Any thoughts?

 

[BarefootFriar]

Seems like I read that Notty does a better job at lower temps. So maybe ferment at 62-64? instead of 68? (Or, in degrees Celsius, shoot for 17-18 rather than 20). Other than that, it looks pretty good to me.

I'm sure someone else will be along eventually to reverse what I just said, so I defer to them.

 

[signpost]

I'm wondering about the diastatic power of your mash. I have a feeling toasting the half pound or so of 2-row might denature the enzymes. I'm not 100% sure on that though. But if it does, then you might need to up the non-toasted 2-row to compensate. Granted all the dark grains you have in there don't really need to get converted, but the toasted 2-row and the oats will make the mash take a little longer to fully convert the starches to sugars.

So, as I see it, you have 2 options. 1) add some more 2-row to boost the diastatic power of your mash; or 2) stir the mash regularly and give it extra time to complete conversion. It'll probably be fine as it is, but giving the mash some extra time would be a good idea if you want to get the most gravity out of your grains.

I've never used Notty, so I can't help you with that question.

 

[dcp27]

you should have enough diastatic power, it varies between maltsters but 2-row is usually around 120-140DP and you only need about 30DP for conversion. if you can fit more malt tho, i'd do that since its cheaper than extract anyway. unless its already done, i'd toast the oats vs the 2-row tho.

i'd reduce the notty temp too at least to start. if notty gets much over 20C it can be pretty gross

 

[progmac]

personally, i'd want some level of caramel to balance out the chocolate, roast, and black patent. i would fear it might be kind of bitter like burnt coffee as it is. maybe 3/4# of C60

 

[CanuckBrwr]

Thanks for all the feedback. I've already brewed this, so I'll put feedback on here once I bottle and sample it. I'm considering adding some crystal to better balance the flavours the next time I do this, but that'll depend on how the end product tastes.

I'm wondering about the diastatic power of your mash. I have a feeling toasting the half pound or so of 2-row might denature the enzymes. I'm not 100% sure on that though. But if it does, then you might need to up the non-toasted 2-row to compensate. Granted all the dark grains you have in there don't really need to get converted, but the toasted 2-row and the oats will make the mash take a little longer to fully convert the starches to sugars.

I assume my diastatic power was enough because my efficiency seemed to be reasonably good (I estimated around 75%-80% based on the OG that I ended up with). I had assumed a lower efficiency since this was my first time doing it, so I overshot my target OG, but there are worse things that could happen Anything that I'm missing here regarding diastatic power? If my OG goes up, does this mean that I have enough 2-row in the mash, or could It just be that I'm dissolving non-fermentables? Is there a good way to know how much 2-row I need?

 

[signpost]

I assume my diastatic power was enough because my efficiency seemed to be reasonably good (I estimated around 75%-80% based on the OG that I ended up with). I had assumed a lower efficiency since this was my first time doing it, so I overshot my target OG, but there are worse things that could happen Anything that I'm missing here regarding diastatic power? If my OG goes up, does this mean that I have enough 2-row in the mash, or could It just be that I'm dissolving non-fermentables? Is there a good way to know how much 2-row I need?

Sounds like my questions about the diastatic power were indeed nothing to worry about. Like dcp27 wrote, the diastatic power of the 2-row is many times more than is needed to convert just the 2-row, so there were plenty of enzymes to take care of the rest of the grain bill. I'd be interested in an answer to your last question, as well.

And if 2-row has as much diastatic power as dcp27 wrote that it does, then why do people suggest using some 6-row to get more diastatic power when mashing pumpkin (for example)?

 

[dannyhawkins]

Canuck, it is brewed and done I see that but I was going to suggest you skip the gelatin as its a dark beer. Nobody will be able to tell or care if the oatmeal clouded the brew a bit. Unless you regularly treat with finings and enjoy it I would say skip the hassle. If it were me I would skip secondary altogether and just primary one month then bottle from there. By the way I like that shot of Columbus hops in there, ill have to try that with my next stout. It sounds like I would taste good even though I don't know what smells sound like.
Good luck

 

[dcp27]

And if 2-row has as much diastatic power as dcp27 wrote that it does, then why do people suggest using some 6-row to get more diastatic power when mashing pumpkin (for example)?

i'm pretty sure that's just a holdover from when there used to be a bigger difference or people that just like extra safety. like i said, it varies between maltsters, but for instance Briess 2-row is 140DP and their 6-row is 180DP, so plenty of coverage

 

[CanuckBrwr]

dannyhawkins:

The gelatin was a mistake. I normally use that for clearing, but in this case I'm not even going to transfer to secondary (no point, as you pointed out). Thanks for the confirmation though. Always nice to hear that I'm not completely out to lunch.

.

 

[CanuckBrwr]

So I brewed this, and the sample after 1 wk in the fermentor was great. Good mouthfeel and good taste. However, after 2 weeks in the Primary the taste changed considerably for the worse. It now has a fairly strong off taste which I think is from the high alcohol. I tried fixing it by adding some lactose, and I think this helped some but not completely. Any advise? Any ideas on how to avoid this in the future.

After 1 week, SG = 1.020 or so
After 2 weeks, SG = 1.015
OG = 1.067

Am I correct in assuming that this off taste is just high alcohol from a slightly high OG and good attenuation? Any other causes?

 

[signpost]

Well, if you are getting a 'hot' alcohol taste, it isn't simply a matter of high attenuation. Chances are it fermented a little too warm/fast. And the best solution is to just let it age a bit, and the alcohol taste will mellow over time.

On the other hand, if it tasted fine after 1 week and then the off taste became apparent at the 2 week mark, my guess is that it isn't the 'hot' alcohol taste that some people get from too hot/fast fermentations. And without a more detailed description of the off flavor, I'm not sure I can help much.

 

[CanuckBrwr]

Thanks a bunch for all the help. Bottled this and have been drinking it for a week or two now, and all the alchohol/wine tastes seem to be gone. I'm guessing it could have been from fermenting hot or jut from the high ABV, but it seems to have mellowed considerably now.

Tastes quite good, but I'll probably still try a few small tweaks the next time I make it. Might post the recipe in the recipe DB once I get it fine tuned. If anyone else brews this with or without changes let me know. I'd be interested in what others think.

Thanks again for the feedback