Imperial Stout problems

[KBald77]

Im still in my first few batches, but I tried to make an Imperial stout which included 19 lbs. of Malt/Barley for a 5 gallon batch. The estimated ABV was 10.8%, but the OG came out at 1.031, which is giving me an estimate of around 4.8%.

I am trying to figure out what it is I may have done wrong to make this happen so the next time I can fix this. What is the cause when something doesn't hit the expected ABV by a longshot?

 

[LLBeanJ]

Unless your grain was not crushed, something is way off here.

You say OG was 1.031, but for an imperial stout that sounds more like FG to me. What were your OG (prior to fermentation) and FG (after fermentation) readings?

 

[buzzerj]

Yeah 19 lbs. of malt for a 5 gallon batch should be a very large O.G. more like 1.080 or above. That's a whole lot of malt. You need to give us more details of your process. Mash Temp and duration? You sparged with how much water at what temp? How much liquor did you lauter into the boil pot? Boil duration. Your wort was cooled to what temp during hydrometer measurement of your O.G. What was your volume in your primary? Did you add any water?

 

[KBald77]

LLBean: The attempt was for an Imperial Stout and I know that it did not turn out as such. That was the OG before fermentation. It is currently fermenting, so I don't have a Final yet.

Buzzerl: I brought 6.5 gallons to 156 degrees and added 14 lbs. of 2 Row, 3 lbs. of flaked oats, 1 lb. flaked barely, 1 lb. chocolate malt, and .5 lb black malt for 90 minutes. I strained out all the malt, brought back to a boil, then added hops. Not sure where I went wrong exactly. Are there usual problems that come up when dealing with this much malt?

 

[olotti]

Did u do brew in the bag? Did u not squeeze out the extra wort? Did u take a refactometer reading cuz those can b way off based on temp of the wort when taking the reading. There is something amiss here as 1.030 shouldn't even b ur fg that's still high for a huge ris. Did u stir ur grain well? What do u use for a mash tun? Lots of questions to ur process but I'm sure we'll b able to figure it out.

 

[buzzerj]

OK you didn't mash the grains you steeped them in 6.5 gallons. Usually during mashing a big bodied beer like an Imperial stout you want a thick mash so your ratio of grain weight to mash water volume in quarts is 1:1. So 1 lb. of malt to 1 quart of water. For 19.5 lbs. of malted grain (your flaked oats and flaked barley isn't malted but for sake of argument lets say it's still 19.5 lbs. total) you should have used a volume of water go 19.5 quarts. 19.5 quarts = 4 gallons and 3.5 quarts. You used 6.5 gallons (26 quarts) so you had a thin mash 1 lb. malt to 1.33 quarts. If you figure your flaked oats and flaked barley as not really malted the ratio is 1 lbs. grain to 1.68 quarts. Thats below what you would mash a pilsner or a cream ale. But you are trying to make an imperial stout. So steeping the grain with such a thin mash even for 90 minutes won't draw out all the sugars. You didn't sparge the malt it sounds like either so the grains were not washed of their sugars. If you would have strained out the malt and sparged (washed) it with 170 degree water you would have captured more sugar in your wort. That assumes you would have steeped the grain in less water than your entire 6.5 gallons. So you left a lot of good sugar still in the malt and not in the wort. You basically have a very dark somewhat roasty (golden) ale. If you are not too far along with this batch you could go get some dry malt extract cook it up in a small volume of water and feed it to your wort thereby bumping up the final %ABV. But going from 4.9 to 10.8% is a bit much. You could try to get it up in the 6-7% ABV range and call it good.

Now a word of advice. Many brewers start out and really are tempted to make that great big beer. Push that envelope. And you can do that, not a problem. Someday. But for now, work on your process. Your all grain process really requires mashing. Read up on it. If you want I can help you out as can others in here. Propose a recipe, and describe what your process will be and let us suggest things prior to you jumping in and asking afterwards. Read John Palmers How to Brew. It's free to read right here on the internet: http://www.howtobrew.com/intro.html Read section 3 and Chapter 16 to understand mashing. Practice on smaller beers to get your process down. You will be successful. After you have the equipment and the process, you can try bigger beers like Imperial Stouts. Then you will be wildly successful and we can help you along the way. Best of luck on your next batches. We're glad to work you through it before you start.

 

[KBald77]

Thank you, Buzzerj, This seems really useful! Ill have a read and follow up if I have more questions. I tried to sparge but was having issues so I tried to find a work around. Maybe that ruined everything.

Thanks!

 

[Sir-Hops-A-Lot]

To save this batch I'd add some extract as soon as you can.
I'd estimate around 7 pounds.
There are lots of threads on how to build a mash tun. Check those out.
And keep on brewing! Your penniless friends depend on you!

 

[buzzerj]

One other point. An Imperial Stout with a 10.8% ABV will really take you the better part of a year to age to get to it's optimum. Then you will also not find it drinkable in that more than one pint or bottle will get you full and tipsy. So think of it this way. You made a sessionable RIS that will come into it's zone much earlier than a big bodied beer like one 10.8% version! At least you can drink more than a few bottles without passing out.

I think of it this way. Louis Armstrong was probably the greatest musician of the 20th century. Some people will dispute that but then his recordings from the 20's and 30's are not of a quality to really judge against modern technology. But what made him great was not that he could play his horn loud. He rather was a master of the nuance of his music. He could play within his limits like no other. The true master brewer isn't the one who can make the biggest beer. It's the one who can make all his or her beers to the complete excellence of their style. Those who really know how to capture the nuance of the style be they big or small beers. Smaller beers are not necessarily the easiest to make. Some can be quite a challenge depending on the style. You can always shoot for the fences with a big robust brew like a Russian Imperial Stout. But there are many other stouts, porters, pale ales and the like that you can learn from and hone your process with. Think for now process, process, process. Yes I was overly influenced by a brewer who said make the same beer 10 times to get your process down. I couldn't do it either. But his message did stick. Brewers who have done less than 10 batches, less than 20 batches even should work on process. Don't jump into all-grain right away unless someone experienced in all-grain can brew with you. All-grain is easy once you understand the process and work at it and develop the nuance your equipment and know how will allow.

 

[danath34]

OK you didn't mash the grains you steeped them in 6.5 gallons. Usually during mashing a big bodied beer like an Imperial stout you want a thick mash so your ratio of grain weight to mash water volume in quarts is 1:1. So 1 lb. of malt to 1 quart of water. For 19.5 lbs. of malted grain (your flaked oats and flaked barley isn't malted but for sake of argument lets say it's still 19.5 lbs. total) you should have used a volume of water go 19.5 quarts. 19.5 quarts = 4 gallons and 3.5 quarts. You used 6.5 gallons (26 quarts) so you had a thin mash 1 lb. malt to 1.33 quarts. If you figure your flaked oats and flaked barley as not really malted the ratio is 1 lbs. grain to 1.68 quarts. Thats below what you would mash a pilsner or a cream ale. But you are trying to make an imperial stout. So steeping the grain with such a thin mash even for 90 minutes won't draw out all the sugars.

How is what he did steeping rather than mashing? Just because he used 1.33qt/lb?that's not even terribly thin. I've used 2qt/lb or more with no issue. There is no set mash thickness to separate a mash from a steep. The things that separate a mash from a steep are temperature control and enzymatic activity, i.e. mashing a base grain in addition to the specialty grains.

OP: was the malt crushed before you mashed it?

Also, you brought the water up to 156 then added the grain. The grain is going to drop your mash temp to the lower 140's. To hit your 156 mash temp, you will need water more in the range of 168 degrees. You can get conversion at lower. Mash temps, but it takes much longer. You might have been at such a low temperature that you didn't get much conversion in the time you gave it.

 

[buzzerj]

Yes I agree with Sir Hops. I built a beautiful functional mash tun from an Igloo Cube 12 gallon cooler and copper tubing for a manifold. I never attempted a RIS with it as even that size of a cooler may be a bit small for a big beer like that. But that mash tun served me very well. If I can do it, you can do it. My advice is a big big beer like a RIS will stretch your all-grain capabilities usually by the size of the equipment you have on hand. Try a partial mash RIS first using 6 lbs. LME and some DME to keep the quantity of malt you need to mash low enough for you to handle. You will still get a good result. I have every confidence you will.

 

[buzzerj]

Right this mash temp must have been affected by that much grain temp. But he also could have added heat. As to the issue of the grain/water ratio, his effective malt volume was 15.5 lbs. to 26 quarts of water. That is 1.68 quarts to 1.0 lb of malt. Thats a thin mash. Without effective sparging of the malt when withdrawn,most of his wort sugars stayed with the malt and not with the liquid wort. The flaked oats and flaked barley also made washing of the malt harder. Four lbs. of flaked grains is a whole lot to try to wash even if you did sparge through a mash tun.

 

[danath34]

1.68 qt/lb is nothing compared to most BIAB brewers, who all get excellent efficiency. It's definitely not the mash thickness. Even if it did negatively effect the efficiency, it wouldn't drop it to 1.030!

 

[LLBeanJ]

1.68 qt/lb is nothing compared to most BIAB brewers, who all get excellent efficiency. It's definitely not the mash thickness. Even if it did negatively effect the efficiency, it wouldn't drop it to 1.030!

This ^

This is not a mash thickness problem.

I don't recall reading anywhere in this thread what the OG was supposed to be, but assuming ~1.100 was the target, 19 lbs of grain in a full volume mash with no sparge should have easily yielded 1.080 without even trying, assuming the mash temps were where they needed to be.

I brought 6.5 gallons to 156 degrees and added 14 lbs. of 2 Row, 3 lbs. of flaked oats, 1 lb. flaked barely, 1 lb. chocolate malt, and .5 lb black malt for 90 minutes.

I think this right here is likely your problem. If you started with 156° water and then added 19 lbs of grain, the temp of the water/mash is going to drop quite a bit, probably around 8-10°. You didn't say you added heat to bring it back up to your intended mash temp, so I am assuming you didn't and ended up mashing too low and that hindered the conversion of starches in the grain to fermentable/non-fermentable sugars resulting in an abysmally low OG.

 

[ScrewyBrewer]

My first instinct was to ask whether the grains were crushed or not too. Yesterday I brewed a five gallon eBIAB batch of Cascadian Dark Ale that came out with a 1.076 original gravity using 19 pounds of Pale Ale malt, a pound of roasted malts and a pound of flaked wheat. I mashed it all for 90 minutes at 149F in eight gallons of water. To use 19 pounds of grain and wind up with 1.031 original gravity is very odd.

 

[KBald77]

How is what he did steeping rather than mashing? Just because he used 1.33qt/lb?that's not even terribly thin. I've used 2qt/lb or more with no issue. There is no set mash thickness to separate a mash from a steep. The things that separate a mash from a steep are temperature control and enzymatic activity, i.e. mashing a base grain in addition to the specialty grains.

OP: was the malt crushed before you mashed it?

Also, you brought the water up to 156 then added the grain. The grain is going to drop your mash temp to the lower 140's. To hit your 156 mash temp, you will need water more in the range of 168 degrees. You can get conversion at lower. Mash temps, but it takes much longer. You might have been at such a low temperature that you didn't get much conversion in the time you gave it.

Hi Danath - The malt WAS crushed before I mashed it. That isn't the issue. The temperature might have a been a bit off, but I did get to 170 before adding the malt, but with the amount of malt I added maybe it still went too low. I was adding heat to keep it in the 150's though.

 

[ballsy]

Something is wayyyy off. Doesn't matter the technique, or that it was BIAB, or that it didnt have a mashout. That big of grain bill should not end up at .030....has to be a miscalculation is my thought. Let it ferment out and condition for few months, willing to bet the ABV will tell truth then. Out of curiosity, is your hydrometer accurate? Have you put it in distiller water? What was temp of the wort when you took the OG reading? Not that this would throw it off that many points, but curious.

 

[d3track]

Out of curiosity, is your hydrometer accurate? Have you put it in distiller water? What was temp of the wort when you took the OG reading? Not that this would throw it off that many points, but curious.

That's along what I was wondering? If using a hydrometer those pieces of paper can shift if it gets banged around.

Did you spin it to keep it from sticking to the side of the tube?
Or read the Brix scale?

These are goofs that could easily happen, I still think using a hydrometer is a PITA and every time the conversation in my head starts "are you doing this right?"

 

[LLBeanJ]

Hi Danath - The malt WAS crushed before I mashed it. That isn't the issue. The temperature might have a been a bit off, but I did get to 170 before adding the malt, but with the amount of malt I added maybe it still went too low. I was adding heat to keep it in the 150's though.

Well, if you were adding heat to maintain your mash at the desired rest temp, then I'm with the others who suspect either: a) measurement error (e.g., faulty hydrometer reading) or b) bad measurements due to faulty equipment (e.g., hydrometer FUBAR or thermometer not accurate at mash temps).

There is just no way that 19 lbs of crushed grain mashed for 90 minutes in the 150s is going to only yield 31 gravity points. Either the mash temp was cooler/hotter than you think, which killed your conversion or the 1.031 gravity reading was not correct, either due to a bad hydrometer or user error.

 

[KBald77]

Well, if you were adding heat to maintain your mash at the desired rest temp, then I'm with the others who suspect either: a) measurement error (e.g., faulty hydrometer reading) or b) bad measurements due to faulty equipment (e.g., hydrometer FUBAR or thermometer not accurate at mash temps).

There is just no way that 19 lbs of crushed grain mashed for 90 minutes in the 150s is going to only yield 31 gravity points. Either the mash temp was cooler/hotter than you think, which killed your conversion or the 1.031 gravity reading was not correct, either due to a bad hydrometer or user error.

It was definitely 19 lbs. I had just purchased it and used all of it. I guess the thermometer could have been off. Maybe hydrometer reading was messed up, I took the test at 70 degrees so it wasn't the temperature, but I am not sure what else could cause a misreading with a hydrometer.... All very strange.

 

[ballsy]

I guess at this point, the only viable solution is bottle it when done and let sit for 3-4 moths then mail out samples to all of us for some constructive feedback! Honestly, you'll be able to tell at that point if it was a measurement error vs mash error.

 

[danath34]

It was definitely 19 lbs. I had just purchased it and used all of it. I guess the thermometer could have been off. Maybe hydrometer reading was messed up, I took the test at 70 degrees so it wasn't the temperature, but I am not sure what else could cause a misreading with a hydrometer.... All very strange.

Yeah something is off. Either user or equipment error. I'd start with the hydrometer. Check it in water and make sure it reads 0. Also make sure you didn't accidentally read Brix, because 30 brix is 1.120 SG which is a lot more believable.

Then check the thermometer. I had a thermometer start reading 130F at room temperature because moisture got in the probe which was not waterproof. Oddly enough, a few days later after it dried it seemingly read correctly again.

 

[FatDragon]

When the question is, "Why did I undershoot/overshoot my gravity by (insert large number)?" the answer is almost always, "You didn't." The problem is almost always one of measurement, and when the beer is really way off target, it's usually blatant user error of the, "turns out I never added that second 3.3 lb bottle of LME," variety.

In this example, your measured efficiency, for a 90 minute mash, no less, is in the 30-40% range. That's hard to believe unless you left a significant portion of the wort in the mash tun and topped off your kettle with plain water. Unless you measure it after fermentation (there are a couple hacker diy methods, or professional labs that'll give you ABV measurements), you'll never know for sure, but once the beer is done, you'll probably find that it hits a lot harder than your measurements tell you it should, because it's likely that your OG was higher than you measured.