100% Oat Beer

[BottledAnger]

I'm going to be attempting a 100% oat beer pretty soon.

10# oat malt
1# golden naked oats
1-3# rolled oats

I bought the first two ingredients already and I'm just thinking through the logistics. I know Bugeater brewed a 100% oat beer once and talked about it on The Session at one point. I have no idea when the episode was, but I specifically remember being on the train at SFO airport when I heard it. But I digress...

So I'm hoping Bug can chime in with some methodology and tips. And all other feedback is welcome too.

My plan is to just get some rice hulls mixed in with the crush, slowly begin recirculating the strike water, slowly add the crush, and cross my fingers. This is pretty much my standard mash in technique and I never have stuck mashes. Even my pumpkin beer with 4# canned pumpkin and over 2# of flaked grains doesn't stick.

Thoughts?

[MNHazmat]

Will the oats convert themselves in the mash or will you need to add a couple of lbs of 2 row for enzymes?

[BDawg]

Malted oats are on par with 6 row for diastatic power.
This will work. Not sure how it's going to taste. I think it will be interesting nonetheless.
Make sure you step mash it with a nice 20-30 min rest at 121F to break down all that protein.
I'd mash to the low side, like 149 or so because you will have a shitload of mouthfeel from the
oats as it is.

[snowcapt]

May as well toast some ofem too,
Drjnk

[captain carrot]

I brewed an oat beer with a friend years ago. Two things pop into mind.
Oat malt kernels are small. Tighten your mill gap or run them thru twice.
The shelf life was pretty short. I don't remember why but don't sit on it.
Good luck!

[BottledAnger]

Malted oats are on par with 6 row for diastatic power.
This will work. Not sure how it's going to taste. I think it will be interesting nonetheless.
Make sure you step mash it with a nice 20-30 min rest at 121F to break down all that protein.
I'd mash to the low side, like 149 or so because you will have a shitload of mouthfeel from the
oats as it is.

As I understand it, it's not so much protein that makes oats difficult, it's beta-glucans. Here's a quote from How to Brew (pg 145, 2006 ed):

"Most of the beta-glucan in barley is degraded during malting (from 4-6% by weight to less than .5%), so it is usually not a problem for well-modified malts. The same applies to malted wheat, oats, and rye."

But usually when people use oats they're using unmalted rolled oats. Since most of my mash will be malted oats I'm wondering if the glucan rest will be necessary. To be honest, I'm thinking about just single step infusion because I want to see what the full oat experience is like!

I'm also considering roasting maybe .5-1# of the oat malt making this into more of a stout. I've never roasted my own malts before so I'm trying to decide if doing too many experiments on one batch is wise.

[BottledAnger]

So I didn't end up brewing the 100% oat beer but I figured I'd share my experience in case somebody else can benefit. I stupidly realized that 11# of grain would only yield about a 1.040 beer, so I decided to brew an oatmeal stout. Here's the grainbill (rounded percentages and weights):

36% maris otter 6#
50% oat malt 10#
5% golden naked oats 1#
2.5% chocolate malt .5#
2.5% pale chocolate .5#
2% roasted barley .5#
2% english extra dark crystal 160L .35#

1oz 11.7% chinook at 60, 10, and 0 (15min hot whirlpool before chilling)

pitched with 1968 at 62*

As other people had mentioned, the oat malt is a very long kernel that isn't very plump. After running it through the mill, it seemed like there was still about 25-35% still uncrushed. I ran it through again and it looked pretty good. I also noticed that it has quite a bit of husk. Because of this, I actually decided not to use any rice hulls in the mash.

I also used some online data to assume that the oat malt had a pppg of about 29. I planned for 65% efficiency (usually get 75%) and mashed at 1.5 qts/pound. Mash flow was not a problem at all - in fact, the oat malt is so husky that I feel like the grain bed was my easiest flowing I've ever had.

I hit my numbers right on so it looks like my estimations were pretty decent, though I'm a little weirded out that my efficiency apparently suffered so much from my norm. But at least I aimed low - nothing's worse in brewing than missed expectations.

The batch smelled very unique throughout the brew - kinda horsey or like a barn. Not too strongly, just a light stank to it like sun-dried hay and husky grain. Maybe a little corny.

Looking forward to the results - I've been trying to brew classic styles with Jamil-like perfection for awhile now so it was fun to go off the deep end with this beer.