Monday, June 18, 2012

Toasted Oat - Coffee Stout

Not every new idea is a good idea. Adding oats to the boil of the first iteration of the Coffee Oatmeal Stout resulted in a nice oat-aroma, but the mouthfeel lacked the silky/oily texture that a hearty stout demands. For this second batch, my primary alteration to the recipe was a switch from half of a pound of oats added to the boil, to two and a quarter pounds in the mash.

No need to mill grains that have been rolled, like these toasted quick oats.In addition to changing the way and amount of oats that were added, I also switched the type of oats. Flaked or rolled grains, which are steamed, don’t make a big flavor contribution compared to grains that have been roasted or toasted as a result of Maillard reactions. Initially I planned to toast the rolled oats in my oven (as I did with my failed Oatmeal Cookie Brown Ale), but Jacob suggested buying commercially toasted oats to avoid the task of toasting ~400 lbs ourselves every time we want to brew a 30 bbl (930 gallon) batch. A quick online search turned up Country Choice Oven Toasted Quick Oats. It turns out that these oats are rather lightly toasted, not much darker than the usual Quaker Oats, although they do have a slight oatmeal-cookie aroma. It will be interesting to see how much of that comes through in the finished beer.

Note the combination of small bits of grain, and relatively intact husks.Other than the changes to the oats, the rest of the recipe received just a few minor tweaks. A slightly higher gravity, and more bitterness to match. I added more CaraMunich and chocolate malt, to complement the higher gravity. I also pitched S-04 because I didn’t have time to make it to the homebrew store for a pack of WY1968. Although that may not be a problem again since a new homebrew store recently opened just a few blocks from my house (in what will be the tasting room of 3 Stars Brewing).

I'm amazed how much character we got from two ounces of coarsely crushed coffee beans in the first batch. If anything the perception has grown more potent as the beer sits on tap. Rather than reducing the amount of coffee for this batch, I am planning on shortening the time spent in contact with the coffee beans (24 hours instead of 36). This beer may yet need another rebrew or two, but if the sample I pulled after a week of fermentation is any indication, we may be down to subtle tweaks (like coffee variety).

Some video from the brew day of the first oatmeal stout made it into a short documentary about the DC Homebrewing Scene (as well as some passion about the topic from Nathan, Thor, and myself).

Black House #2

Recipe Specifics
Batch Size (Gal): 5.50
Total Grain (Lbs): 12.38
Anticipated OG: 1.060
Anticipated SRM: 40.9
Anticipated IBU: 41.9
Brewhouse Efficiency: 77 %
Wort Boil Time: 60 Minutes

60.6% 7.50 lbs. Maris Otter
18.2% 2.25 lbs. Toasted Oatmeal
8.1% 1.00 lbs. Briess Roasted Barley (300 L)
6.1% 0.75 lbs. Briess Chocolate Malt
4.0% 0.50 lbs. CaraMunich Malt
3.0% 0.38 lbs. Crystal 90L

5 ml HopShot (Extract) @ 55 min.

0.50 Whirlfloc @ 15 min.
0.50 tsp Yeast Nutrient @ 15 min.
2.00 oz Coffee Beans @ 1 days

DCL Yeast S-04 SafAle English Ale

Water Profile
Profile: Washington, DC

Mash Schedule
Sacch Rest - 65 min @ 154 F

Brewed 6/9/12

Pre-toasted oats, Country Choice Organic Oven Toasted Quick Oats

Added 3 g of chalk and 2 g of baking soda after mashing for 15 minutes because the pH was about 5.1 at room temperature (4.8 at mash temp). This brought the pH up to about 5.4 at mash temp (5.1 at mash temp).

Slow sparge, should have picked up some rice hulls... runnings looks a bit milky at first, but cleared up eventually. Still collected gallons of 1.052 runnings from a double batch sparge (didn't drain entirely due to the slow runnings).

Added one 5 ml HopShot of hop extract for bittering. Not much of a hot break.

Chilled to 65 F, pumped in 45 seconds of pure oxygen, pitched 1 packet of (rehydrated 105 F water) S-04, and left at 63 F ambient to ferment.

6/15/12 Boosted temp to 65 F to ensure it finishes out. Looks a bit paler than expected.

6/23/12  Added 2 oz of crushed Mocha Java Blend coffee beans in a sanitized hop sock, not weighted. Racked to a flushed keg 22 hours later.

8/9/12 Really close to my ideal coffee oatmeal stout. Could be a bit thicker, and slightly lighter on the coffee aroma though.

1/12/13 Brewed a third iteration of this recipe.


Anonymous said...

Cook's Illustrated rated that Oat brand's old fashioned version last in a tasting, I'm not sure if that would carry through into a beer. S-04 has a rehydration temp of ~27C +/-3C, in other news I'm bored and should probably lighten up :P.

The Mad Fermentationist (Mike) said...

Interesting, making actual oatmeal with the toasted oats the texture wasn't great, but the flavor was fine. Looks like I need to get some Bob’s Red Mill if these don’t work out.

You are correct on the rehydration temperature, although doing it warmer (as many other dry yeasts suggest) resulted in strong fermentation by about 12 hours, so no worries.

Lowell Brewing Co. said...

Looks delicious...stouts are overlooked so much in the summer!

Anonymous said...


I'm about to brew a strawberry witbier and plan on using 2.25 lbs. of flaked oats (for a 10 gallon batch). The recipe I'm using calls for a protein rest (at 122 degrees). I noticed that you did not do a protein rest, instead just a 60 minute sacc rest.

Can I skip the protein rest? I have no way to do a multi-step mash infusion.

Any advice would be much appreciated.


The Mad Fermentationist (Mike) said...

You certainly may end up with some haze, but that isn't a big concern in a wit. In most cases I don’t think step mashes are a requirement with modern malts (even given the high protein content of unmalted wheat), usually they are something to be dealt with as you are dialing in a recipe to a precise target.

Good luck!

Anonymous said...


Good point you make about the unmalted wheat...

My recipe calls for 10 lbs. flaked wheat, with 11 lbs. pilsener malt and 1 lb. munich to finish out my bill (again, 10 gallon batch). Given the flaked oats AND flaked wheat, can I still do a single infusion mash? 153ish?

Sorry to bother, but this one has me scratching my head.


The Mad Fermentationist (Mike) said...

Your bigger issue with that recipe is going to be the lack of amylase enzymes. 2-row malts are usually only good to convert the starches from about 35-40% of their own weight in adjuncts, and you are well over 50% (Munich only has enough to convert itself). If you want to use that much wheat, I would swap out a couple pounds for malted wheat (which is loaded with enzymes). Even still I would probably hold the conversion temperature for 90 minutes or so.

Hope that helps, good luck!

The Mad Fermentationist (Mike) said...

In my last comment the math was atrocious. Rather than talking about the percentage of adjunct compared to the base malt, I was talking about the percentage of the adjunct compared to the total grist. It takes a Diastatic power (DP) around 40 for a malt to self-convert, but it is safest to have an average DP around 60.

In the case of your recipe there is 11 lbs of malt that is probably around a DP of 110, and 1 lb around 50 (both of these will vary by maltster). The 12.25 lbs of unmalted grains have none of the required enzymes. That puts your average DP around 52. Not too bad, but still worth an extra-long conversion rest. You can do a starch-iodine test before running off if you want to be sure.

Anonymous said...

Thanks for the advice. I thought that may have been too much unmalted grain. I think I will scale back the flaked wheat to say 6 lbs. and add 4 lbs. of wheat malt (and 2 lbs. of rice hulls for sparge), and hold it for 90 minutes to be safe.

My wife is giving birth to our first child in Sept. and this is going to be the celebratory “It’s a girl! Strawberry Witbier.” Pink labels and all.

Thanks again!

Vince D. said...

I'm curious why you didn't go with a commercially available toasted oat, like Simpsons golden naked oats. I found them to be nice in an oatmeal stout:

The Mad Fermentationist (Mike) said...

As far as I am aware, Golden Naked Oats are a light crystal malt made from oats. While I like the flavor, it is very different than what you get from toasted unmalted oats. I really like GNO in lighter beers (they were in the hoppy wheat I recently brewed) but their flavor wasn't what I was looking for in this batch.

Jamie said...


Just curious when you added the HopShot?

The Mad Fermentationist (Mike) said...

I added the HopShot with 55 minutes left in the boil. For future reference the recipe always contains all of the hop amounts and timings.

Jamie said...

I don't know how I missed that. I apologize. Thank you though.

Andrew said...

What was the finishing gravity this time around?

The Mad Fermentationist (Mike) said...

The final gravity was a bit lower than the first batch, 1.012.

Tichols said...


If I were to replace the hopshot with whole hops, what and how much would you add, and when.

I've "only" done 16 batches, and I have no idea what a hopshot is :D Still so much to learn :)

This looks right up my alley, sounds very tasty :)

Thanks, and have a nice weekend,
Thomas Nichols - Denmark

The Mad Fermentationist (Mike) said...

HopShots are 5 ml hop extract syringes that Northern Brewer sells. You could substitute the bittering hop of your choice (Magnum, Warrior, Northern Brewer, Target etc.). I find the bitterness from extract to be a bit smoother than actual hops, so you might bring down the IBUs to around 35. You could add the hops at the same time (55 min from the end of the boil), but the exact amount will depend on the AA% of your hops, a recipe calculator will figure it out for you.

Good luck!

graymoment said...

I was wondering if you could help me with a recipe question considering how well you know the flavor profile of this beer. I brewed this recipe almost identical to how you have it posted, except I used almost half of the amount of roasted barley (to get to the same SRM) because my homebrew shop only sold 595L, and I used WLP007. I made some stupid calculations with my sparge water (i use RO) and acidified the sparge (a lot). a sample after primary fermentation naturally tasted fairly acidic and sharp; not good. I intend to add chalk when kegging to help neutralize the acidity, and I'm also considering doing something else with the beer to round out the flavor. I'd be open to suggestions. One idea is to not do the coffee addition so as not to make it any more acidic than it already is. Another idea is to maybe add wood (maple or oak), a vanilla bean and/or other flavorings to the beer. Any thoughts? One thing to note, my efficiency suffered on this one and I ended up with a 1.053 OG.

The Mad Fermentationist (Mike) said...

Doubling the lovibond and halving the amount may get the color close, but the flavor will be different. You'll get more of a sharp/acrid roast with the darker roasted barley.

With my high carbonate water I've never had an issue with low pH in a dark beer. I only acidify the sparge on really pale beers because I've never had an issue with tannin extraction (especially because I usually batch sparge).

Adding chalk is probably your best bet to raise the pH now. Have you taken a pH reading? Do it slowly, I know Kai has written about chalk taking awhile to work in the mash, it may be the same in the finished beer. Even a couple hours might not be a bad idea between additions.

Best of luck!

graymoment said...

Unfortunately I hadn't planned the brew far enough out to order a lower lovibond malt online, so I got stuck with the local homebrew shop substitution phenomenon (I think we've all been there). My local homebrew shops do not stock much of a selection to speak of with ingredients compared to online stores.

I haven't taken a pH reading (I don't have a meter yet, but it's next on the list). What pH do you target with this beer? Would you still add the coffee given the higher lovibond and acidic blunder (which I'll attempt to correct with chalk), or maybe forego it in this scenario?

The Mad Fermentationist (Mike) said...

Most clean beers finish in the low 4s. It isn't something I usually measure for my clean beers, just interested if you had. I doubt the coffee would drop the pH, so it is just your call from a flavor standpoint. Vanilla is a panacea for off-flavors, it might add some perceived sweetness that could help the beer out. Hope that helps.

Anonymous said...
This comment has been removed by a blog administrator.
graymoment said...

Yes, that helps. Vanilla is exactly what I was thinking. It works well for that purpose in beer, baked goods, oatmeal, you name it. Thanks.

Allison said...

Do you worry about contamination from the coffee? Other than sanitizing the hop sock, do you do take any other precautions?

The Mad Fermentationist (Mike) said...

There is certainly a microbial risk when adding coffee (or anything, including hops) on the cold side. I've yet to have issues, but that isn't to say that I never will. Roasting your own, or getting it as fresh as possible would be best. At Modern Times we'll be roasting our own beans, which will give us advantages both from a flavor and process standpoint.

Jason Thompson said...

Hey Mike,

Thanks for the awesome site! I'm working on a water profile for a similar oatmeal stout recipe. I havent come across much regarding flaked oats and itss effect on mash ph. Have you noticed that the oats contribute a larger ph drop than a base malt like MO?

Thanks for all the info bud.


The Mad Fermentationist (Mike) said...

I haven't noticed the influence of oats on mash pH, but I really haven't used them much in paler beers. Usually roasting is what increases the acidity of a grain. With how pale flaked oats are, I doubt they have a large influence. Good luck!

Anonymous said...

Brewed, packaged, and tasted! Thanks for the recipe. I added 1 oz crushed Guatemala Finca El Injerto - a Bourbon varietal roasted by Stumptown of Portland, OR. Toasted oats addition was great, even though I feared over toasting and even burning them. PS cant wait to locate some canned MTB beers so I can finally taste what i've been reading about.

The Mad Fermentationist (Mike) said...

Glad to hear it turned out well! I hear the beers in the cans are the best batches yet. I've just got a few test runs in the fridge, looking forward to getting some of the real deal too!

Charles Wiseman said...

Hey Mike,

Just wondering if you'd recommend using these pre-toasted oats or if you get a better toasted oat characteristic from roasting them yourself.

The Mad Fermentationist (Mike) said...

Given the option, you'll get much more character and control toasting oats yourself.

Jon Lambert said...

Did you have a problem with a stuck mash using that much flaked oats (18%)? I've heard using a lot of oats can get pretty gummy.

The Mad Fermentationist (Mike) said...

I don't have a problem with 18% oats, but if you are worried a few ounces of rice hulls is certainly cheap insurance. We've had more problems at Modern Times with Fortunate Islands, and its 50% wheat malt.

Ryan Walker said...

So I'm thinking of brewing an imperial oatmeal stout and this recipe looks awesome. I'm thinking of just doubling everything and hitting all the percentages in the grain bill (and switching out Maris Otter for Golden Promise). Have you done this? Would that be how you might go about making an imperial version of this?

Mark Froehlich said...

I brewed this recipe about 3 weeks ago and i wanted to see how low your FG eventually got to. Mine won't seem to be going any lower than about 1.030 which seemed a little high to me. Did yours end up that high or do you think my fermentation is stuck?


Mark Froehlich said...

Not sure if my previous comment posted so I apologize if this is a repeat. But long story short, I brewed this 3 weeks ago and fermentation has stopped at 1.030. I was wondering if yours ended that high or if mine might be stuck. Thanks in advance for the help!

The Mad Fermentationist (Mike) said...

Sorry, I had to turn comment moderation on!

Ryan, Modern Times released a Mega Black House at 10% ABV. Not sure what they did, but I likely would go up 1.5X on the specialty malts and double the oats and base malt.

Black House usually finished around 1.022 for me. I think all the specialty malts and oats dilute the diastatic power of the Maris Otter (which is relatively weak due to over-modification). Swapping in some American 2-row would be a good way to address this as would optimizing the mash: pH, relatively thick, and at least 60 minutes. At this point you might want to pitch rehydrated US-05 to dry to finish it out!

Anonymous said...

I am curious if you have any experience with Wyeast 1469 and if you would recommend it with this recipe. I've never used S-04 (or anything else from Fermentis). I have used Wyeast 1968 and 1469 and those are my go-to strains for these styles. I have some 1469 on hand right now.

The Mad Fermentationist (Mike) said...

I brewed a Landlord clone with it many years ago. It was tricky to work with (krausen wouldn't drop), and that didn't give a good indication of how it would perform in a dark beer, but if it has worked in similar beer, go for it! And let me know how it turns out!

Sean Malloy said...

Great article, as usual!

Whenever I brew an oatmeal stout, I toast the oats a few days ahead of time. Before mashing, I also let them sit around 120 F for 15 min. The combination of toasting and pre-cooking leads to a great mouthfeel!

Anonymous said...

Not sure if it’s from my choice of coffee bean or from the s-04, but mine had a significantly tart finish, red wine comes to mind. I used a Guatemalan, light roasted bean for the coffee addition and fermented at 65f for 2 weeks, 1.063 to 1.020 FG with 2 packs of s-04. Sanitation is as good as possible, no signs of pellicle. Just can’t figure out where the tartness is coming from...would be appreciative if anyone had any insights on this. Not bad at all really: coffee aroma, roasted sweetness then a tart and dry finish.

Anonymous said...

Update: after a couple weeks in the keg, the tartness has faded and the finish is rather clean (still a touch of tartness) and it is what I would want in a breakfast stout. Seems like I either kegged a little early or perhaps my yeast got too warm. Any ways - great recipe, thanks for sharing!

Nick P said...

Thanks Mike, looks great, will be my next stout. Wondering why you chose not to add cold pressed or brewed coffee? Enough coffee style taste from dark grains? 9BBL, brewery? Thanks mate, great webpage. Nick.

The Mad Fermentationist (Mike) said...

I find adding coffee beans to the beer is the easiest way to introduce coffee flavor without risking oxidation (which can result in a green-pepper flavor). It also seems to produce a more long-lived coffee flavor, perhaps through the extraction of alcohol-soluble flavors. That said, for our first batch of coffee beer (Bangun) at Sapwood Cellars we added some cold-brewed coffee in addition to the beans to help saturate the flavor. Scott recently wrote a post about that batch on his blog (link).

Nick P said...

Great info thank you Mike. Will visit Sapwood if I holiday in the US. Look forward to it.