Russian Imperial Stout Stuck Fermentation?

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Vegetarisk

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Attempted a russian imperial stout and undershot the target O.G. of 1.080 (mine was 1.0603, most likely to adding a little too much water to the wort)

5 gallon extract kit
6.6lb dark LME
2lb dark DME
8oz maltodextrin

8oz caramel 60l
8oz roasted barley
8oz black patent

I steeped the grains around 165F, which in hindsight may have been a little high. I did not roll the grains before steeping either.

Pitched an 11.5g packet of rehydrated dry yeast at about 70F and fermentd at 67F (lowest I can go right now) Violent fermentation began within 12 hours to the point the plastic airlock cracked and I had to put a brick on top of the bucket lid to keep it from blowing off. Replaced the airlock and bubbling continued for about a week and a half. Now about 2 weeks after brewing, I took an SG reading of 1.033 (adjusted for hydrometer temp variation) which seemed high after 2 weeks. I'll continue to monitor and roused the yeast over the next few days, but if the SG remains the same, is there anything I can do to bring it down to my target F.G of 1.017 - 1.020?

Will raising the temp help? Is it too late to pitch more yeast after 2 weeks?
 

jekeane

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About your OG if you followed the directions properly and filled to the proper volumes ie it was a 5g batch and you made 5g not 6g then your OG was likely 1.073-1.080. When you add top off water it is near impossible to thoroughly mix the water and wort. You almost always will get some sort of stratification until the yeast is well into doing its thing.

Even though you had a vigorous fermentation it is more than likely you under pitched your yeast a beer that size definitely needs at least 2 packs of 11.5g yeast. Pitching rates are super important to good beer so next time check out a yeast calculator like mrmalty or brewersfriend.

Your only option other than gently stirring and raising the temp a bit to see if you can get the yeast going again would be to pitch a small starter 250-500ml of similar yeast at high krausen. According to the brew strong podcast I listened to last night about this topic you would even make a starter with dry yeast for this to be effective.

There are many other possible reasons as to why you are stuck under aerating, to many non fermentable sugars due to steep temps or old/bad LME DME are possible but honestly you have to work hard to miss a OG by that much with an extract batch and I would be surprised if it wasn't just a bad hydrometer reading from wort stratification.
 

slayerextreme

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I'm 5 days into my 1st brew....I started with the Brewers Best Russian Imperial Stout.....I ended up with an OG around 1.074-1.076 (temp corrected) I had VIOLENT fermentation that required me to modify my airlock with the hose that came with my brewers best kit and create a blow-out tube, which I dropped into a bucket of sanitizer....I'm now on day 5 and now have the normal airlock in place and showing minimal fermentation....I will be giving my primary a slight swirl daily (not required )....and plan on racking to my Carboy in another 5 days....I know its not required....I JUST WANT TO SEE MY BEER!!!!!!!!...and my local brew supplier said it would help some with removing some of the particles in the brew (I drink from bottles and dont use a glass)......I plan on taking a SG reading after 10 days in the secondary to see if my expected FG has been reached....so 10 days in primary..10 days in secondary...10 days in bottles.......the hardest part for me is keeping from taking the lid off the primary bucket!!!!!
 

jekeane

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a RIS wont be all that special after 10days in the bottle. You'll be wanting it to age a good bit. Also you'll likely want to consider purchasing some glass wear. Bottle conditioned homebrew will have a good bit of yeast sediment from carbonating. The rocking motion from sipping will stir this up and you will get a yeasty flavor to your beer, and quite possibly the runs. Drinking from a bottle also removes the aroma aspect of the drinking session which is a major component of the overall flavor. If you exclusively drink from bottles it is unlikely you've experienced major flavor aspects of the beers.
 

sictransit701

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I brewed this same kit and got the same results. Primary for 2 weeks. Waited 4 weeks in secondary for it to ferment down, but never happened. Bottled last night. Hopefully no bombs. It's in the bath tub.

OG = 1.065
FG = 1.030
I pitched two packs of s04 rehydrated

I did a full boil. No top up water needed. Don't know how My og was so low. I put the recipe in brew smith and it said my og should have been 1.057. That's a lot different from the recipe.

I have read how dark extracts have a lot of unfermentable sugar. Maybe that's why the fg was so high.
 

BarrelAgedForrest

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Attempted a russian imperial stout and undershot the target O.G. of 1.080 (mine was 1.0603, most likely to adding a little too much water to the wort)

5 gallon extract kit
6.6lb dark LME
2lb dark DME
8oz maltodextrin

8oz caramel 60l
8oz roasted barley
8oz black patent

I steeped the grains around 165F, which in hindsight may have been a little high. I did not roll the grains before steeping either.

Pitched an 11.5g packet of rehydrated dry yeast at about 70F and fermentd at 67F (lowest I can go right now) Violent fermentation began within 12 hours to the point the plastic airlock cracked and I had to put a brick on top of the bucket lid to keep it from blowing off. Replaced the airlock and bubbling continued for about a week and a half. Now about 2 weeks after brewing, I took an SG reading of 1.033 (adjusted for hydrometer temp variation) which seemed high after 2 weeks. I'll continue to monitor and roused the yeast over the next few days, but if the SG remains the same, is there anything I can do to bring it down to my target F.G of 1.017 - 1.020?

Will raising the temp help? Is it too late to pitch more yeast after 2 weeks?
Curious, thought steeping grains is going to add little if any points SG wise, why didn't you mill them? Secondarily as someone mentioned above 2 packs or a starter may have been your best bet. My current brew is an imperial Porter, my OG was 1.084. I used one pack of dry yeast but made a starter with it 2 days prior and it fermented to almost below 30 within 2 days. So good future knowledge. Definitely at least try to get it further down with another starter in it no reason not to try at this point!
 

BarrelAgedForrest

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I'm 5 days into my 1st brew....I started with the Brewers Best Russian Imperial Stout.....I ended up with an OG around 1.074-1.076 (temp corrected) I had VIOLENT fermentation that required me to modify my airlock with the hose that came with my brewers best kit and create a blow-out tube, which I dropped into a bucket of sanitizer....I'm now on day 5 and now have the normal airlock in place and showing minimal fermentation....I will be giving my primary a slight swirl daily (not required )....and plan on racking to my Carboy in another 5 days....I know its not required....I JUST WANT TO SEE MY BEER!!!!!!!!...and my local brew supplier said it would help some with removing some of the particles in the brew (I drink from bottles and dont use a glass)......I plan on taking a SG reading after 10 days in the secondary to see if my expected FG has been reached....so 10 days in primary..10 days in secondary...10 days in bottles.......the hardest part for me is keeping from taking the lid off the primary bucket!!!!!
Should leave it on the yeast cake for more then 10 days, at least 14. You want the yeast to clean up after itself!
 

pdog44450

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I brewed this same kit and got the same results. Primary for 2 weeks. Waited 4 weeks in secondary for it to ferment down, but never happened. Bottled last night. Hopefully no bombs. It's in the bath tub.

OG = 1.065
FG = 1.030
I pitched two packs of s04 rehydrated

I did a full boil. No top up water needed. Don't know how My og was so low. I put the recipe in brew smith and it said my og should have been 1.057. That's a lot different from the recipe.

I have read how dark extracts have a lot of unfermentable sugar. Maybe that's why the fg was so high.
A 35 point spread with a 1.030 FG is scary... In the future, when brewing a 1.060+, ferment 4-6+ weeks primary before secondary. I'm going to make the assumption that you racked too early before the yeast cleaned up and finished fermenting. 2 weeks for that big of a beer is way too quick.

I brewed a 1.080 RIS while back. 8 weeks primary fermented And 12 weeks bottle conditioned and it's now delicious, have tried one every 2 weeks and it gets better every time. If you try to cut corners with big, full bodied, heavy beers you will be disappointed in the end. Even with all the specialty malts it finished under 1.020.

What was the room temp you fermented at? Since you pitched 2 packs of dry yeast, I'd conclude you racked to secondary too early, had really bad yeast, didn't properly oxygenate the wort before and after pitching, or fermented really cold (kind of ties into the first one). Your calculations say you have 4.6% abv, which is less than a Budweiser, and 52% attenuation which is extremely low.
 
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