Having just brewed my porter, I was still thinking heavy beers for cold nights. I also had some WLP 002 English Ale Yeast sitting in the fermenter and having just brewed a flavorful porter I needed to pick a style that was darker and could use that yeast. Stout it is! I was thinking about a coffee stout but ultimately decided on an oatmeal stout since it is a recognized style in the BJCP guidelines and my goal is to brew one beer of each type.
Researching the Oatmeal Stout style
I don’t drink a lot of stouts but I have consumed enough to generally know what they are supposed to taste like. But to be certain I checked my two go to references for creating recipes of a specific brew style: the Brewer’s Association Style Guidelines and the Beer Judge Certification Program Style Guidelines. From the Brewer’s Association:
“Oatmeal Stouts are dark brown to black. Coffee-like roasted barley and roasted malt aromas are prominent. Caramel-like and chocolate-like roasted malt aroma should be evident. Fruity-ester aroma is not perceived to very low. Hop aroma is optional, but should not overpower the overall balance if present. A roasted malt character which is caramel-like and chocolate-like should be evident, smooth and not bitter. Hop flavor is optional, but should not overpower the overall balance if present. Hop bitterness is medium. Oatmeal is used in the grist, resulting in a pleasant, full flavor without being grainy. Fruity-ester flavor is very low. Diacetyl should be absent or at extremely low levels. Body is full.”
Ok so pretty similar to a porter except a stout does have a roasted barley flavor while a porter does not. I had heard at some point “black patent for porters, roasted barley for stouts” and this seems to reflect that. Roasted barley, caramel malt, chocolate malt plus oatmeal for mouth feel. Bittering hops but no aroma hops.
Note: after researching for this post I realized I didn’t notice or pay attention to the very low to no Fruity-ester flavor mentioned above. I wondered about the yeast I was using and looked at it a little more carefully. While great for all kinds of English style ales and in particular stouts, White Labs says this strain is not particularly good for an Oatmeal stout. I’m guessing it’s because of the potential fruitiness this can impart. I’m fermenting in the mid 60’s and probably over pitched a little (big starter) so hopefully this will reduce the amount of fruity esters that are produced. Either way the beer should taste good, I just hope it’s true to style.
Back to researching wort creation. So that’s what the Brewer’s association said what does BJCP say:
“Characteristic Ingredients: Pale, caramel and dark roasted malts (often chocolate) and grains. Oatmeal or malted oats (5- 20% or more) used to enhance fullness of body and complexity of flavor. Hops primarily for bittering. Can use brewing sugars or syrups. English ale yeast.”
Pretty much the same. This mentions using an English Ale yeast and in their description say low to medium-high fruitiness so possibly my yeast mistake will work out ok after all. Both descriptions mention full bodied (kind of goes without saying) so I’ll use a higher mash temperature. I went with crisp maris otter for the base malt, crystal 80L malt, pale chocolate malt and roasted barley along with fuggles bittering hops and flaked oats (full recipe below). I aimed for about 10% oats in the grain bill, more than that and I might have issues with the mashing. Then it was just a matter of plugging these ingredients into Beer Smith and tweaking them until I got the Original Gravity (OG), International Bitterness Units (IBU) and Standard Reference Method (SRM) were in the ranges I wanted.
A note about oats
I said above to use oatmeal, do I mean the same oatmeal you would buy at the grocery store? Well yes and no. There are many types of oatmeal and oats available on the market today: instant oatmeal, old-fashioned oatmeal, steel cut oatmeal, rolled oats and flaked oats. In general for brewing I use instant oatmeal or flaked oats that I buy at the homebrew store.
Why? What’s the difference between these different oats? You can use any oatmeal or oats while brewing you just may have to cook them first. Oats contain all kinds of starches and gums that need to be gelatinized first to successfully extract them in the mashing period. Rolled, flaked and instant oats have all gone through this process already and are ready to just dump into your mash tun with the other grains. Steel cut oats or some non-instant oatmeals need to be cooked first before being added to your mash. This is why I generally use flaked oats or instant oatmeal, they’re just easier.
The gums and starches in oats can cause another problem for the homebrewer: stuck mashes. The oats work to thicken the grain bed slowing the amount of water that can be filtered through it. Sometimes it is so thick that it stops the flow of sparge water completely. Here are two ways to avoid this:
- Slow sparging – whether you batch sparge or fly sparge, doing so at a slower rate will reduce the chance you’ll have a stuck sparge. If you drain wort off the grain bed, faster than the sparge water is able to filter through you’ll develop a vacuum which will compact the grain bed causing the stuck mash.
- Rice Hulls – rice hulls added to the grain bill won’t do much to affect flavor or sugar content but they will act as a bulking agent to keep the grain bed from compacting too much.
What do you do if you get a stuck mash? Well many references will tell you basically to start all over, dump the wort back into the mash and lauter tun (MLT) and sparge with it after stirring up the grain bed again. I’ll tell you what I did. If I had a stuck mash early in the process I probably would’ve started over. My stuck mash occurred after I had collected 7.2 gallons of wort and I was looking to collect a little over 7.6 gallons. I just closed the valve on my MLT, stirred up the grain bed, collected the first 2 pints or so and added back on top of the grain bed to make sure it was running clear and then finished collecting my remaining .4 gallons.
Probably not the greatest thing but I also wasn’t about to start all over with so little to go. Time will tell if that was a good idea or a bad one but my OG came out on target and the wort tasted fine.
I already described in a previous post how I harvested the yeast from the porter I brewed and made a starter with it in preparation for brewing this stout. Other than the previously mentioned stuck mash, my brew day went as planned. I tried out the variations to my cooling system that I mentioned in my last brewday and they seemed to work well. The grain bag I filled with my grain bill at the brew store had the name Laura written in giant letters down the side of it. The clerk mentioned that they may have just given this beer a name, they did.
Notes from Brew Day
Most things went well. Still tweaking this new cooling system, I’m interested in researching the best configuration for an immersion chiller in a later post (stainless or copper, 3/8″ or 1/2″, 25 ft or 50 ft). I ended up going through 30 lbs of ice, but there was still a significant water savings compared to just running the hose. The chiller and ice bath were also very effective.
I had the stuck mash I mentioned so next time I’ll probable add rice hulls and collect wort even more slowly than I did. Normally I refrigerate the starter and decant off the liquid, pitching the yeast cells that have collected at the bottom. I forgot to do this this time and attempted to decant some of the starter off, but ended up pitching around 1 Liter of yeast starter wort so we’ll see if that affects the flavor. Measured OG was 1.064 which was almost exactly the predicted 1.065. Pitched the yeast at 68°F. Fermentation started about 12-18 hours after pitching and so far things are looking good. Here’s to another great tasting beer!
Laura - An Oatmeal Stout - Recipe Details
|Batch Size||Boil Time||IBU||SRM||Est. OG||Est. FG||ABV|
|5.5 gal||60 min||33.8 IBUs||37.2 SRM||1.065||1.024||5.4 %|
|Name||Cat.||OG Range||FG Range||IBU||SRM||Carb||ABV|
|Oatmeal Stout||13 C||1.048 - 1.065||1.01 - 1.018||25 - 40||22 - 40||1.9 - 2.5||4.2 - 5.9 %|
|Pale Malt, Maris Otter||10 lbs||74.07|
|Caramel/Crystal Malt - 80L||1 lbs||7.41|
|Oats, Flaked||1 lbs||7.41|
|Pale Chocolate Malt||12 oz||5.56|
|Roasted Barley||12 oz||5.56|
|Fuggles||2.5 oz||60 min||Boil||Pellet||4.5|
|English Ale (WLP002)||White Labs||67%||65°F - 68°F|
|Mash In||156°F||45 min|