GF Oatmeal Stout (partial mash)

[glutarded-chris]

GF Oatmeal Stout (partial mash)

Ok, summer is almost over, so longer brew days in Florida are survivable. Going to wait for a nice “chamber of commerce” mid 70’s day in October or November and begin my partial mash regiment. To date I have never brewed anything darker than an amber ale so I am thinking on doing a partial mash adaptation of Igliashon’s “No Nonsense Stout” to break into the dark. I am trying only a little bit of juju for those familiar with Igliashon’s original post. https://www.homebrewtalk.com/f164/no-nonsense-stout-323755/

Rather than roast the oatmeal, my plan is to get the roasted flavors from roasted grain in the mash. Would like to hear any comments and suggestions on this.

5.5 gallon pitching volume
3.5 gallon boil volume

Mash:
4.0 lb pale millet malt
0.5 lb dark roast millet malt
0.5 lb medium roast millet malt
1.0 lb pale buckwheat malt (cereal mashed)
1.0 lb oats (cereal mashed)

Added to boil:
3.5 lb sorghum syrup [1lb at 60 min and the remainder at 15 min]
Note: the amount of sorghum is adjusted as needed based on actual mash yield
2 lb Belgian Candy Syrup D180 [15 min]
0.5 lb maltodextin [60 min]

Hops (33 IBU calculated):
0.5 oz Columbus @ 60 minutes
0.5 oz Columbus @ 20 minutes

Other:
1 tab Whirlfloc
3 tablespoons yeast nutrient

Yeast:
1 sache Safale S-04

BG: 1.050
OG: 1.060

 

[billl]

Are you planning on home roasting the millet or buying it? My first attempt at home roasting went OK, but ended up more malty without having much real roast character to it. The dark and chocolate roasted grains I got from grouse were dramatically more roasty and had burnt character. I think it has to be a really dominant flavor in the grain to make a big impact in a 5 gallon batch.

The dark belgian candy sugar has a very fruity taste - plum, raisin, date - mixed with just a hint of chocolate or coffee. It's very smooth without any of the sharp edge that a traditional stout has. Once the beer is fermented, you might try a glass with a touch of cold pressed coffee added to get that extra bite.

I'd say the IBU is a little on the low side, but that is personal preference. A general rule of thumb for stouts is that the IBU is about 75% of the OG. 45IBU would be my starting point for a 1.060 beer

 

[glutarded-chris]

Thanks for the feedback!

My plan is to get the grain from Grouse.

I took the IBU I plan directly from the original recipe. I was a little worried that the IBU would be too low because my experience is that GF grain just does not have the "malt flavor" of regular beer and a little extra hops goes a long way. To be honest, I have never had a "real" stout so I am flying blind. If I like it I don't care if it has an authentic taste. I may take your advice and boost the IBU and I will note your rule of thumb.

I have never used that much dark belgian candy sugar but on first attempt I decided to stay true to the original and then make any changes later if need be. My primary concern was if I have a reasonable amount of roasted grain to approximate contribution of the roasted oats, since my oats are simply added to the mash unroasted. What do you think of the grain mix?

 

[billl]

By all means, defer to someone who has actually brewed the beer in question. I brew a decent amount of beer, but am new to GF.

As for home roasted oats vs grouse, that really depends on who was doing the roasting. That dark roast millet from grouse is jet black and very much like a roasted barley like you would find in Guiness. The medium roast is something more like a brown malt you might see in a brown porter. (I know, not very helpful if you haven't tasted those. ) I think that mix would be appropriate for a stout and probably will provide more roast character than I would get trying to home roast some oats.

 

[ffd907]

Here is a picture of my pre boil wort from my all-grain Grouse malts chocolate oatmeal stout. I used 16 lbs total in my grain bill (not counting the 1.6lbs of rice hulls for lauter) and ended up with an OG 1.062. I used 2 lbs of medium roast and 1 lb of dark roast. I also added some Vienna, crystal and light roast to try and layer some flavors as well as 8 lbs of base pale malt. Mmmmmm taste of the wort pre ferm was amazing, caramel, chocolate and some coffee notes. It's now in secondary with 8 oz cacao nibs. Grouse malts are awesome however Avery's mash regime needs adjusting. I'm not able to get good attenuation and the two all-grains before the stout only got down to 1.022 and 1.030. I skipped one rest with the stout this time and added amylase to the fermenter as well as pitching two packets of yeast, on rehydrated and the other sprinkled dry on top.
You really need to use 6-10 lbs of pale millet to get the OG up. The other pic is the finished product and color like motor oil.

 

[ffd907]

Pre boil wort

 

[glutarded-chris]

Interesting all grain version.

If you did not use other sugars etc. looks like you got about 22 ppg which is pretty good and used about 6% of your fermentables from dark roast. Using 50% roasted and crystal grain seems a little high which might be why you are having difficulty getting attenuation. Some are having difficulty with over-attenuation with millet malts. Could be there is an optimum percentage of pale malt in there somewhere to discover. Let us know how this batch ends up in FG and how it turns out in general! If you like it you should post it in the recipe section. We need more successes posted there!
https://www.homebrewtalk.com/f240/

 

[billl]

I think the mash schedule needs some work too. My stout is sitting at 1.023 right now. That was with a main conversion rest at 140. The extract level was really solid, but the fermentability is just too low.

BYO just had an article about optimal temps for enzymes. Apparently alpha and beta both have considerably lower optimal temp ranges in pure starch solutions vs mashes. I wonder if the 100% boiled mash acts more like pure starch than a regular mash? I think I'm going to drop into the low 130's for my next attempt and see how that works.

 

[ffd907]

Yep, I just kegged my stout last weekend and got a 1.028 on it. So that has been my delema with millet all-grain batches all three finished 1.026-1.032 after two weeks primary and two weeks secondary. So I've been getting good apparent conversion in the mash but not complete enough for the yeast to finish their job. I too will be experimenting with those newer temps. Taste is there though, just a bit sweeter than expected without Malto or sugars.

 

[Legume]

Adding a couple of tablespoons of AMG-300 (amylase) to the mash might help to increase the fermentability of your wort...its worth a try.

 

[glutarded-chris]

With respect to enzymes, I got advice to use Diatase enzyme (from EC Kraus). Now I use the liquid diatase and don't use powdered amylase.

Bottom of post #6 of https://www.homebrewtalk.com/f164/poor-efficiency-millet-buckwheat-460357/
Also post #17 of https://www.homebrewtalk.com/f164/dialing-millet-mash-467399/

 

[glutarded-chris]

Ok, I brewed the oatmeal stout attempt on October 12. Long brew day as I thought I could combine 2 brew days into one day with one clean up. I staggered two separate mashes in time. The oatmeal stout mash went well but the second one suffered a bit on the timing of the rests and got comparatively poorer efficiency. I did learn with experience that the timing of the rests is important and got 15 gallons total fermenting by the end of the day.

The main difference from the plan at the beginning of this thread is that my LHBS did not have D180 syrup so I had to use D45. To compensate I bumped up the dark roast millet in the mash.

I mashed 7 lb of grain and got about 24 ppg yield

5.5 gallon pitching volume
3.5 gallon boil volume

Mash:
4.0 lb pale millet malt
0.7 lb dark roast millet malt
0.3 lb medium roast millet malt
1.0 lb pale buckwheat malt (cereal mashed)
1.0 lb Bob’s Red Mill GF rolled oats (cereal mashed)

Added to boil:
2 lb sorghum syrup [60 min]
Note: the amount of sorghum was adjusted based on actual mash yield
2 lb Belgian Candy Syrup D45 [20 min]
0.5 lb maltodextin [20 min]

Hops (42 IBU calculated):
0.55 oz Columbus (16.3%AA) @ 60 minutes
0.55 oz Columbus (16.3%AA) @ 20 minutes

Other:
1 tab Whirlfloc
3 teaspoons yeast nutrient

Yeast:
1.5 sachet Safale S-04

BG: 1.040 at beginning of boil for bittering hops
BG: 1.099 at end of boil for flavoring and aroma hops (after late additions of fermentables)
OG: 1.058

This batch used about 22% of the gravity contribution from sorghum syrup.

Will see how it turns out in a few weeks!

 

[glutarded-chris]

This batch finished at FG: 1.006 so about 6.8% abv. Serious chocolate taste with the gravity sample! Hope I didn't over do it with the dark roast grain. I put half in a 2 gallon corny and the rest in bottles in case it needs to condition a long time.

 

[mergs]

Chris if you wouldnt mind could you describe the steps you took during the mash?

I want to place an order with grouseco soon but I'm still trying to wrap my head around these millet mashes.

Plan is to biab but the mash details should be similar

 

[glutarded-chris]

The method I currently use is essentially an adaptation of Andrew Lavery’s method that many of us have used as a foundation. http://www.glutenfreehomebrewing.org/all_grain_brewing_tutorial.php

I have tried to simplify with single infusion but just end up back with a step mash and with bringing some of the enzyme rich wart forward to the last rest, which is what Andrew Lavery did. I use buckwheat for the head retention properties so I had to adjust the process to accommodate cereal mashing of the buckwheat. Some of the information I got from these two threads ended up being fundamental:

https://www.homebrewtalk.com/f164/poor-efficiency-millet-buckwheat-460357/

https://www.homebrewtalk.com/f164/gf-ag-first-attempt-questions-463175/

I use a partial mash with 6 to 8 lb of grain, which offsets 4 to 5 lb of sorghum syrup. With 8lb of grain, I can use a voile bag and easily lift the grain bag without pulleys etc. Buckwheat increases the potential for stuck sparge so being able to use the bag gives extra peace of mind. With a partial mash I also don’t have to be concerned with collecting thin wart and boiling down for hours. I sparge and collect 3 to 4 gallons of wart and just boost with sorghum syrup and/or brown rice extract solids. I think for true all grain you really have to have your process down. Partial mash is more forgiving but does force you to use sorghum syrup and/or brown rice extract.

Not saying my method is the best but here it is.

It is basically a step mash with:
25 min rest at 105-110F
25 min rest at 125-135F
20 min rest at 150-155F
5 min above 170F
90 min rest 130-140F

I crush the millet grain with a 0.010 inch gap and the buckwheat with a 0.045 inch gap on the rollers. My Carona mill works just fine it just takes longer and gets grain dust everywhere.

Put three gallons of water into an ice bath well in advance.

Dough in 6 lb millet with 7.5 quarts of ~110F strike water in a kettle that can take the final mash volume and can be heated (no bag). This begins the first 25 min rest.

While the main mash is in its first rest I cereal mash the buckwheat. Add 2 lb buckwheat to 5 quarts boiling water. Boil for 10 minutes stirring constantly.

When the first 25 min rest is over, combine the buckwheat to the main millet mash. A few quarts of the chilled water will be needed to get the combined mash down between 125 and 135F for the second 25 min rest.

When the second rest is complete, stir in 2 quarts of boiling water. This is just to add some extra water for collecting enzyme rich mash water and to add some heat. Let the mash settle for a few minutes and then scoop off 4 quarts of water from the top and put in a sealed container like a water jug. This is the enzyme rich mash water that will be added back later. Try to get mostly mash water but I don’t worry if some mash is collected also. Put the decanted mash water container into the ice bath.

Heat the mash to 150F and hold for 20 min rest.
Heat the mash to between 170 and 180 for 5 minutes.

Add the gallon of clear chilled water to the mash first to bring the temperature down.
Then transfer the mash into the mash cooler lined with the voile bag.
Then add the chilled mash water, which should bring the mash down below 140F.
Add more chilled water or hot water as required to start the final rest between 135 and 140F.

Add Diatase Enzyme to the mash. This is probably optional but I think it helps with the conversion.

Hold the final rest for 90 minutes. This seems to be critical as I have not been able to get above 20 ppg without a long final rest.
At final rest there should be about 2.6 quarts per pound of grain or just over 5 gallons of water with the 8 lb of grain.

Heat one gallon of sparge water to 170F in boil kettle
Pull grain bag and let it drain some (first runnings).
Teabag sparge the grain bag in the preheated sparge water in the boil kettle.
Pull the grain bag and combine total wart in boil kettle.

Note: I squeeze the grain bag to get as much of the precious wart from the grain. Normal advice is not to do this as it can result in off flavors from the husks but I suspect that is more of an issue with barley husks. I suspect it is not much of an issue with millet so I squeeze as much of the goodness out as I can.

It helps to have a boil kettle with volume markings or a calibrated stick to determine the volume of wart collected. Take a gravity reading.

ppg = (gravity points of wart collected)*(gallons of wart collected)/(pounds of grain)

For example with the 8 lb of grain and 4 gallons of 1.045 gravity wart collected I calculated ppg = 45*4/8 = 22.5

I use this and adjust the batch plan to hit my target OG.

It seems complicated but this basic process can be followed with less buckwheat or buckwheat + oats or whatever because you can adjust each rest with either some cold water, heat or hot water. Since it is a partial mash, if you collect a little extra thin wart it does not really matter because you correct for it later.

Sorry for the long explanation!

 

[Osedax]

That is an excellent description of the steps involved! Should help a lot of people that don't quite get our mash process yet. I don't do the steps exactly how you do but, my general procedure and theory are the same.

 

[mergs]

The method I currently use is essentially an adaptation of Andrew Lavery’s method that many of us have used as a foundation.

....

Sorry for the long explanation!

Wow! Thank you!!!

 

[glutarded-chris]

No problem. Hope the information helps you forge your process. Get some grain an give it a go.
You can see from the comments by Osedax that each have their own way but end up variations on a theme.

 

[glutarded-chris]

After 2 weeks carbonating and conditioning I opened a bottle. It still needs more time to carbonate fully in the bottles so I cracked the corny also. WOW serious chocolate taste. Still green and needs some more time but it seems to be a success. A few people who like stouts said that it was good and definitely a stout. I asked for an honest assessment as people tend to say it is good no matter what when then know that you worked really hard on it. They promised that they gave an honest assessment. All agreed it is a little bitter now and needs some time to mellow.

 

[glutarded-chris]

Ok, 6 weeks is the charm. When it was still green, I would drink one and then had to switch to a pale ale. After 6 weeks it has reached it's stride and I can't put it down now. I will also post in the recipe section now that I know I like it.

One thing I noticed is that it does not carbonate like my pale ales. The bottles took 4 times as long and the forced carbonation also seemed to take at least twice as long. Is this normal?
I have seen stouts poured in some pubs that brew their own noticed they often loose their head quickly. Guinness obviously does not have that issue.

 

[KatoBaggins]

Thanks for taking the time to explain the entire process. I'm going to try this recipe. How did do over the last couple of months? Did it continue to improve?

 

[glutarded-chris]

Did not notice much change after 8 weeks. I am rationing it out to myself so it will last another month.

 

[glutarded-chris]

When I brewed my first batch from a kit, the DVD instructions said that the first step was to have a homebrew. That has been my practice ever since. Today was close as I have not brewed all summer (Florida heat). I brewed today and found a bottle of this Stout attempt hiding in the back of the refrigerator. It was my obligatory brew day homebrew. This bottle is almost exactly 3 years old and has been evacuated at least 2 times for major hurricanes (Matthew last year and Irma this year). It was quite good. I am not a huge stout fan, but I have to say this one has survived quite well. I have one last bottle left but don't think I will wait another year to drink it!