Help me autopsy my stout.

[WenValley]

I have ten gallons of oatmeal stout that is undrinkable. See my post in General "Oatmeal Stout Rescue".

It was brewed three weeks ago. I've kegged one carboy, chilled and hit it with CO2 and the off flavor is very pronounced. The taste is a harsh astringent flavor that hits the roof of your mouth.

OK, here's where I think I made a major mistake.

When I went to mash the recipe, I forget to add the two row, which I have here at home, to the grain bill. I ran the grain from the brewshop through the grinder, then added that to the mash tun, there was NO two row in the mash. I noticed that the mash was very thin, and then I figured out that it was missing the base malt.

I went ahead and mashed out the specialty grain, which was 4 lbs munich malt, 4 lbs white wheat, 2 lbs chocolate malt, 2 lbs oats, 2 lbs roasted barley, 1 lb flaked barley, and 1 lb carapils.

When that had mashed for 60 minutes, I sparged and drained it into the boil keg. Then I mashed the two row by itself. 16 lbs. After 60 minutes I sparged that out and added it to the first mash.

I did the 60 minute boil with one hop addition, cooled and transferred to two six gallon carboys.

I've been racking my brain trying to figure out where this batch went sideways, and I'm wondering if mashing the adjuncts with out the base malt would have caused the off flavor.

Was there enough DP in the first mash to convert the starches?

The first mash was at 155 degrees, and the second was at 151. The target was 156 degrees.

Thanks in advance.....

 

[JonM]

I never touch stouts for at least two months after brewday - sometimes three. (Which reminds me: I should start brewing stouts for the fall.)

A three week old stout is way too young to make any decisions about it and I'd expect it to have young off-flavors right now. Just let it sit for a whole.

 

[WenValley]

JonM:
What's your opinion on the split mash issue? I've made this recipe several times in the past, with out this flavor issue. This flavor won't go away with time.

Thanks.

 

[Quaker]

I suspect your super thin mash of just adjuncts caused over extraction of the roasted malt husks. Given time, this will settle out some. Whether or not you had enough diastatic power for full conversion of that first mash would have shown itself in your OG and attenuation rate. Those are my thoughts anyways. Maybe trying a fining agent to accelerate it some.

I haven't made the same mistake yet, but I feared it. Therefore I make a habit of writing on the bag of specialty grains how much base malt to add while still at the home brew store labeling the other ingredients in it. So far, so good.

 

[WenValley]

Thanks Quaker. The gravities were all where I would expect, I don't have the brew sheets here to refer to, but they were within specs.

The first mash was too thin, and if I could do it over, I would have milled the second batch, and added it to the mash tun and extended the mash time. I'm making this a learning event....

I have a new monster mill, and have been buying 2 row by the bag, so I no longer buy it at the brew store. I like your suggestion to write on the bag to "ADD TWO ROW"!!!

I'm going to cry like a baby if I have to pour out ten gallons of stout, but that's just part of the learning curve. Which is much steeper for me than most others....

 

[Yooper]

"I went ahead and mashed out the specialty grain, which was 4 lbs munich malt, 4 lbs white wheat, 2 lbs chocolate malt, 2 lbs oats, 2 lbs roasted barley, 1 lb flaked barley, and 1 lb carapils."

Well, first of all, Munich malt IS a base malt, as is the white wheat, so you're fine there.

There reason for some harshness may be the 2 pounds of chocolate malt and 2 pounds of roasted barley- I find chocolate malt to be very harsh and acrid especially in a young beer.

This should age to a drinkable beer, depending on the rest of the recipe, as those dark roasted flavors do mellow with time.

 

[giraffe]

Are you doing any water chem? If you have soft water the first mash would have been way too low ph, and the 2nd mash too high. Usually thats not going to lead to completely undrinkable, but its there.

 

[RM-MN]

Thanks Quaker. The gravities were all where I would expect, I don't have the brew sheets here to refer to, but they were within specs.

The first mash was too thin, and if I could do it over, I would have milled the second batch, and added it to the mash tun and extended the mash time. I'm making this a learning event....

I have a new monster mill, and have been buying 2 row by the bag, so I no longer buy it at the brew store. I like your suggestion to write on the bag to "ADD TWO ROW"!!!

I'm going to cry like a baby if I have to pour out ten gallons of stout, but that's just part of the learning curve. Which is much steeper for me than most others....

Oh? Are you sure the mash was too thin? I've mashed with as much a 4 qts/pound and it wasn't too thin.

3 weeks from brewing will get you some pretty harsh stout. Let it sit at room temperature for another 3 to 6 months and try it again. I like mine to sit (in bottles) for a year or more as the stout really smooths out then.

 

[Bellybuster]

thats a huge grain bill for a stout and 12% of it is chocolate and roasted. Yup, it'll take a while to mellow.

 

[TheMerkle]

+1 for time.

 

[WenValley]

Thanks to everyone that's offered opinions.

I took a half a cup of oats, and toasted them under the broiler in the oven. Just as I had for the actual batch. I then ground up the oats, added some hot water and I couldn't detect the same off astringent flavor.

I was hoping that I could blame the off flavor on the oats being "too toasty" but my test didn't solve the problem.

I've modified my recipe in BeerSmith and reduced the chocolate and roasted barley.

I'm going to keep this beer and see if it doesn't smooth out, as several of you have suggested. It does seem to be getting better in the keg, and I have five more gallon in primary that can sit for another month or two.

Thank you!