Imperial Stout - First Batch

[DetroitOS]

Need some advice on the following recipe.
3 lbs. Dark Malt
2 lbs. Amber malt extract
4 lb. Can of Mountmellick Irish Stout
1 lb. Crystal Malt 60L
1/2 lb. Roasted barley
1/2 lb Black Patent malt
2 1/2 oz. Super Styrian hops (90 minute boil)
1 1/4 oz. Super Styrian hops (15 minute boil)
1 1/2 oz. Cascade (end of boil)
4 Tbsp. Gypsum
Yeast - Safeale US-05

I started this batch just over two weeks ago. My O.G. was 1.080. After one week my F.G. was 1.031 and has remained that way for a week. The F.G. for this recipe is supposed to be 1.014-1.018. On Friday I swirled the cake and added another pack of hydrated Safeale.

I've learned from this forum you have to be patient and there is nothing wrong with fermenting longer than what the recipe calls for, but I'm worried this batch may not reach the F.G. it's supposed to as it has remained at 1.031.

I didn't have a heat exchanger at the time and it took almost two hours for the batch to cool enough out on my deck in snow. I wonder if the long cooling process has put a wrench in this? When I pitched the yeast the temp. was 85deg. F.

 

[desertbronze]

Need some advice on the following recipe.
3 lbs. Dark Malt
2 lbs. Amber malt extract
4 lb. Can of Mountmellick Irish Stout
1 lb. Crystal Malt 60L
1/2 lb. Roasted barley
1/2 lb Black Patent malt
2 1/2 oz. Super Styrian hops (90 minute boil)
1 1/4 oz. Super Styrian hops (15 minute boil)
1 1/2 oz. Cascade (end of boil)
4 Tbsp. Gypsum
Yeast - Safeale US-05

I started this batch just over two weeks ago. My O.G. was 1.080. After one week my F.G. was 1.031 and has remained that way for a week. The F.G. for this recipe is supposed to be 1.014-1.018. On Friday I swirled the cake and added another pack of hydrated Safeale.

I've learned from this forum you have to be patient and there is nothing wrong with fermenting longer than what the recipe calls for, but I'm worried this batch may not reach the F.G. it's supposed to as it has remained at 1.031.

I didn't have a heat exchanger at the time and it took almost two hours for the batch to cool enough out on my deck in snow. I wonder if the long cooling process has put a wrench in this? When I pitched the yeast the temp. was 85deg. F.

A couple of things: Your attenuation is about 61% and according to your figures this recipe was calculated for 80% attenuation. I would expect a beer like this to get about 70% to 75% attenuation. It is often difficult to get 75%+ attenuation in extract beers. The extract may contain high amounts of unfermentable sugars that the yeast cannot process.

A big beer like this needs lot of yeast at the beginning of fermentation. Probably should have had two or three packets of dry yeast. All the easily fermentable sugars have been eaten by the yeast at this point.

I don't think the long cooling time had any effect on the yeast. 85 degrees F. is a little high for pitching, though the fermentation will usually take right off and be very vigorous for a few days.

Questions: What yeast did you pitch the first time? the second time?

What temperature did you ferment at? What is the temp of the fermenter now?

 

[DetroitOS]

Questions: What yeast did you pitch the first time? the second time?

What temperature did you ferment at? What is the temp of the fermenter now?

Yeast - Safeale US-05
I pitched one pack dry the first time and stored it in the basement at around 62deg F. The second time, almost two weeks later, I pitched the same type of yeast, at one pack hydrated this time, and stored it in a 71deg. F environment where it has been for about four to five days. I didn't see any activity with second addition of yeast. Do you think it's just going to stay at the current final gravity? The taste is also off, kind of a slight nail polish remover finish.

BTW the fermentation was fine for about three days and tapered off from there to a very slight bubble.

 

[DetroitOS]

I took a reading this afternoon and it's still at 1.031. It's been there for a while and there is no activity even though I pitched more yeast two days ago. However the off taste is gone now.

 

[OctopusInk]

you could try wine yeast, that will definitely bring the gravity down, or you could accept that you have a malty beer and condition for a couple of months to remove the "nail polish" taste.

 

[desertbronze]

Yeast - Safeale US-05
I pitched one pack dry the first time and stored it in the basement at around 62deg F. The second time, almost two weeks later, I pitched the same type of yeast, at one pack hydrated this time, and stored it in a 71deg. F environment where it has been for about four to five days. I didn't see any activity with second addition of yeast. Do you think it's just going to stay at the current final gravity? The taste is also off, kind of a slight nail polish remover finish.

BTW the fermentation was fine for about three days and tapered off from there to a very slight bubble.

Solvent like flavors are usually caused by high fermentation temperatures. Your first post said that you pitched the yeast when the wort was 85 deg. F. Even though you placed the fermenter in a 62 deg. F. environment, the fermenter was probably too warm.

I have never been successful restarting a fermentation by adding yeast. I would do one of two things at this point.

1) Brew another beer - a lower gravity easy drinker. Pitch a packet or two of US-05. Let that beer ferment to completion. Then rack this beer onto the yeast cake.

2)Visit your local brewpub or microbrewery - take a sanitized quart jar. Ask for a quart of yeast - most will gladly share. Add that yeast to the fermenter.

 

[Saccharomyces]

Quite simply you underpitched. Ethyl acetate (nail polish remover smell) is a telltale sign. A high gravity wort even if aerated thoroughly will not have a lot of oxygen, so yeast growth is inhibited; you then have few yeast to do the job, they get tired quickly, and drop out before they are done. In addition pitching directly into a high gravity wort makes it difficult for the yeast to hydrate, causing a sluggish start. I would have used three packages of dry yeast, carefully rehydrated.

As you discovered pitching more yeast at this point doesn't help. It's a bit like dropping a couch potato at the top of Mt Everest, he won't survive because he's in the wrong condition for the environment. Yeast quickly adapt to wort, but not to beer; there are few fermentables left for the yeast to chew on and the ones left aren't the first ones of choice for yeast. Any yeast directly pitched at this point will just immediately go dormant and flocc out leaving you with malt syrup.

Your best bet would be to make a progressive starter. Start with a small amount of wort at around 1.040 gravity in a large vessel with plenty of room (you will need it -- an ale pail isn't too large). 2 ounces of DME in 16 ounces of water would be about right. Pitch the yeast into it (no need to rehydrate first at 1.040). Once it reaches full krauesen (about 24 hours), feed it a second helping of fresh 1.040 wort, but add a pint of your beer along with the wort. In another 24 hours, add the same amount of fresh wort as before but then add 2 or 3 pints of your beer. Let it go for 24 more hours, and you will have plenty of fresh yeast which are adapted to your beer! Pitch the whole thing into the fermenter, and it should finish fermenting your beer to a more reasonable FG.

 

[hmmmbeer]

I have the same problem but my F.G is at about 1.022, I am going to let it set for 4-5 months (while I'm deployed) My question is, does anyone think it will start back up at all while in the SF and eat off any of the FG its at now? Or does anyone think this won't be too malty at this FG? Also, the temp I should SF this Imparial Stout at? I figured at the first fermentation temp (stayed between 55F-67F). Now that I think of it, last night we did get a cold snap and it was about 52F when I racked it into the SF, could this be why the yeast stoped? too much flex/too cold to continue?

 

[Calder]

I think it's done. Where did you get the recipe that says it will go to 1.014-1.018?

You have a lot of unfermentables in there.

Dark malt is Light malt with some speciality malts added in. It will be less than 75% fermentable (probably closer to 70%).

Amber malt is Light malt with some crystal malt added in. It is also less than 75% fermentable, but should attenuate more than the Dark Malt.

The Irish stout kit will have lots of dark malts in, so will probably be 70% fermentable at best.

The Crystal and dark malts are probably only about 50% fermentable.

I just did a quick calculation, and I would be surprised if you could get this to ferment lower than 1.026.

 

[Saccharomyces]

I have the same problem but my F.G is at about 1.022, I am going to let it set for 4-5 months (while I'm deployed) My question is, does anyone think it will start back up at all while in the SF and eat off any of the FG its at now? Or does anyone think this won't be too malty at this FG? Also, the temp I should SF this Imparial Stout at? I figured at the first fermentation temp (stayed between 55F-67F). Now that I think of it, last night we did get a cold snap and it was about 52F when I racked it into the SF, could this be why the yeast stoped? too much flex/too cold to continue?

My Gatos Locos has finished at 1.021 to 1.034 depending on the yeast used. I can't imagine an Imperial Stout finishing below 1.020 with all the dark malt and crystal. Let taste be your guide -- if it's too sweet, you can try blending with another batch, use 20% sugar and a highly attenuative yeast to dry out the second batch to use for blending. Or, you can do something like add some cold steeped coffee that will help to offset the sweetness. 1.022 is probably just fine... Heck, I won two awards for my barrel aged version last year that finished at 1.031!

 

[Banjoman76]

Don't use snow only as a way to cool your wort. As you stated it took 2 hours to cool to near pitching temperature. Snow makes a good insulator because of the intricate shapes of the flakes. These shapes trap air in between the flakes as they pile up. These tiny pockets of air prevent air from circulating, thus preventing heat from being transferred by convection. Additionally, ice is a poor conductor of heat. (This is why ice cracks when you put it into a warm drink.) These two factors help to prevent heat from moving through snow.

I have used snow with ice packs in the sink and in a large plastic industrial tote and have added a couple of gallons of cold water and then whirlpooled (stirred the wort) and this will aid the cooling process to under an hour.