I have a DME-based recipe for an oatmeal stout. It calls for rice hulls using a strain and sparge technique. I can see using the rice hulls to make sure the specialty grains don’t clog the strainer; however, if I use a mesh bag for the specialty grains, do I still need rice hulls? Is there any difference in these two approaches in terms of the end result of the beer?
Personally, I’d question any recipe that doesn’t require you to mash the oatmeal with malt, since oatmeal has no enzymes to convert its starches to sugar. This means aside from starch and sticky gums you won’t be extracting a lot from the oatmeal. I know some extract recipes suggest it but IMO it’s a bad approach.
But, regardless, oatmeal has no husk and is full of beta-glucans and will turn into a sticky mess like, well, like oatmeal. If you are trying to actually sparge it may be difficult.
The specialty grains you are talking about have husk material so it doesn’t require a the rice hulls.
I recon the best recommendation would be just to put it all in one bag and steep it then pour hot water over the bag (in a colander or something) to “sparge”.
I doubt you will need hulls, but like majorvices I wouldn’t recommend using oats without mashing with a diastatic malt.
So, based on your comments, would it be best to sparge (not in the mesh bag) and add some DME to the initial water?
You should keep it all in a mesh bag. Rice hulls are not required. As mentioned though, unless some of the grains are base malts capable of converting starches, the oats are going to contribute starches that won’t convert. This is not typically how an oatmeal stout is made and starchy additions may be unusual. If it’s a pound of oats, not sure it will stand out that much. But in practical terms, I’d advise to avoid it.
If you add a lb or two of crushed pale malt to the grains and hold the water temp in low 150s, the enzymes in the malt will convert the starches to sugars and help bring a more typical mouthfeel from the oats.
The two specialty malts added with the oatmeal (not including the roasted barley) are 55°L British crystal malt and British chocolate malt. All of those at 150 degrees for 30 minutes.
The will not convert the oats. You need something like pale malt to do that.
The rest of my recipe calls for Munton’s light DME. It is only a 2.5 gallon batch, so would adding some DME to the steeping process work? If so, how much should I add if there is only 4oz of toasted oatmeal?
This is a pretty basic point. When we mash our base grains, the enzymes in the crushed grain convert long starches to simpler sugars, so the yeast can then metabolize the sugars and produce alcohol and CO2. Without the break down of the malted barley into consumable sugars, you are left with long chain dextrins that are not processed by the yeast. The DME and LME are just processed wort that already went through the process of mashing to produce the syrup and dry version of mashed wort. There are no enzymes left in the DME or LME to convert any of the starches (long chain dextrins).
A half pound of crushed base malt will probably get you there as to the conversion issue.
I hope this helps.
Maybe I am missing something. I am not talking about an all grain recipe, so the items I mentioned are just specialty grains. I was under the impression that those were added for flavor and color and added little to the sugar content requiring enzymatic action???
“Although they add a small amount of fermentables, the flavor, aroma and color of these grains are the main reasons they are added to beers. There are many different kinds of specialty grains. Adding them singly or in combination yields a large range of possible flavors and colors.” [Brew Your Own magazine]
Maybe, but I wouldn’t count on it. There has been supposition that DME will provide the enzymes needed, but I have never seen that verified. And now that I know it’s only 4 oz. of oatmeal, screw it! Go right ahead as planned. I don’t think it will be a major dickchimp. Just keep the knowledge in mind for when you use larger amounts of unmalted adjuncts.
Some specialty grains needs to be mashed. Not things like crystal or roasted malts, but things like oats, corn, or rice do.
Yes, you are missing something: As someone esle mentioned some grains need mashed some can be steeped. Any crystal or roasted malt can be steeped. Pretty much everything else needs mashed. Only “basemalts” contain enough enzymes to convert themselves. “Malt” has been “malted” and the most simple definition of this is it has enzymes. Oat “malt” has enzymes but regular flaked oat doesn’t so it has to be mashed with basemalt. Regular DME won’t have the enzymes needed.
But you can still brew the recipe it’s just that the oatmeal isn’t really doing what it’s supposed to do since you aren’t mashing it. Just throw everything in the bag or sock and steep it - no need for rice hulls.
www.howtobrew.com explains about mashing if you are interested
OK, got it. Thanks for all the comments.
I wasn’t trying to be critical of the recipe or your intentions - I hope it didn’t come across that way, but if it did, I apologize. It’s just that once you have mashed or partial mashed, the “mystique” of all grain will vanish for you. Even so, there are plenty of great beers made from extracts and there is no shame in making them that way. Steve Ruch who contributes here is one such example, based on space and choice - stellar beers I am told. But a little understanding of the all grain process will help you in many ways. Best of luck with your Oatmeal Stout - one of my favorites!
No offense taken. I have a BS in Chemical Engineering from UC Berkeley and prefer straight to the point comments. I have had good luck with DME and have produced some beers that have been given the thumbs up by some pretty picky beer drinkers (mostly my hockey team). Since I haven’t used oatmeal before I wanted to make sure I had the science down pat before jeopardizing my reputation 
I now have to decide on a small amount of base malt to use in the steeping so it won’t impact the final stout. I have a feeling it doesn’t really matter.
[quote=“hennesseystealth, post:16, topic:31020, username:hennesseystealth”]
I’d use the same base malt as what was used to make the extract.
There are some excellent extracts out there that can make pretty good beer. I do make the occasional extract only beer, but am happier with the results using specialty grains. And I usually add some base grain to the specialty grains even if not needed to convert something like oatmeal.