Low attenuation due to extract?

[NGD]

FYI: If you haven't used a pure 02 setup with those small bottles before then just a suggestion. You should only turn the regulator on enough to get some gas through the stone. No need to open the regulator all the way.
I’ve come across a few upset brewers that have wasted a bottle in 1-2 batches because they thought more equals better.

 

[mcleanmj]

FYI: If you haven't used a pure 02 setup with those small bottles before then just a suggestion. You should only turn the regulator on enough to get some gas through the stone. No need to open the regulator all the way.
I’ve come across a few upset brewers that have wasted a bottle in 1-2 batches because they thought more equals better.

Cool thanks a lot!

 

[IslandLizard]

FYI: If you haven't used a pure 02 setup with those small bottles before then just a suggestion. You should only turn the regulator on enough to get some gas through the stone. No need to open the regulator all the way.
I’ve come across a few upset brewers that have wasted a bottle in 1-2 batches because they thought more equals better.

That's excellent advice! ^

@mcleanmj any surface rippling or surface bubbling is from O2 that didn't get dissolved, so all that O2 is wasted. So, yeah, open just enough to see little bubbles (looks like foam) around the stone in your Starsan container. A "0.5 micron" (stainless micropore) stone is best for pure O2 from a tank, not the 2 micron air stone (used with aquarium pumps).

Some have reported that the "regulator" (valve) that's screwed onto those small red tanks tends to leak and empty your little tank during extended storage. Maybe double check or detach between uses.

 

[smata67]

Before going the nuclear option route, might want to boil some water, dissolve about 4 oz of corn sugar, dump it in, and keep things stirred up for a few days. It might get you a few points. I'm guessing not all the way down to 1.026, but who knows.

 

[VikeMan]

Before going the nuclear option route, might want to boil some water, dissolve about 4 oz of corn sugar, dump it in, and keep things stirred up for a few days. It might get you a few points. I'm guessing not all the way down to 1.026, but who knows.

Assuming a 5 gallon batch, 4 ounces of corn sugar (fully fermented) would increase ABV by about 0.35. But it would only decrease the FG by roughly half a point, unless the yeast can suddenly eat the more complex sugars (doubtful) or dextrins (impossible) they previously left behind. I don't see how adding a bit of glucose is going to inspire the yeast to manufacture and use the transports/enzymes they need to handle the bigger stuff. Maybe I'm missing some mechanism you have in mind.

 

[smata67]

"unless the yeast can suddenly eat the more complex sugars (doubtful)"

Yup, that is exactly what happens. I'm surprised you haven't heard of this, it is one of the accepted methods to deal with stuck fermentations. The sugars re-energize the yeast, they are in suspension (since you are stirring), and take an extra bite or two of existing sugars (if they are there) while they are swimming around. I have always been able to knock at least a few points from the baseline (and, as you point out, the gravity is higher after adding the sugar, so more activity than just those points). I once was able to knock off 7 points, having done this twice. It was good enough for that particular batch. These are 7-8% beers though, I rarely stray above that level, since I have yet to do so without having some kind of stuckness that requires babysitting. A 10% beer is going to be very stubborn about re-starting. But this is an easy thing to try.

 

[VikeMan]

The sugars re-energize the yeast, they are in suspension (since you are stirring), and take an extra bite or two of existing sugars (if they are there) while they are swimming around.

It's the re-energizing that I am skeptical of. Perhaps it's the rousing into contact that's actually the driver, assuming the yeast were already in a condition to resume. If they were not, I still don't see how the glucose inspires the yeast to manufacture and use the transports/enzymes they need to handle the bigger stuff. They can't just "take bites" of maltose/maltotriose. They have to transport and break them down into monosaccharides before they can use them. It's not metabolically a freebie.

 

[smata67]

If that were so, then rousing alone would do the trick and it frequently does not. That is always step one, along with raising the temperature. If that does not work, then addition of simple sugars, some nutrient wouldn't hurt, and rousing. If still not satisfied, a starter at krausen and/or dry yeast. For an extremely challenging situation, the much more involved "nuclear option." All but the latter are well known "standard" approaches to dealing with stuck fermentations. I have known about them, used them when needed, for over 10 years. They are common brewing practices, not of my invention, though I'd be happy to take credit for them if there is compensation involved.

 

[VikeMan]

If still not satisfied, a starter at krausen and/or dry yeast.

Well, I can agree with this at any rate. New yeast, in a ready to go configuration, is a great idea if the problem was tired yeast (and not wort fermentability).

 

[Brooothru]

Assuming a 5 gallon batch, 4 ounces of corn sugar (fully fermented) would increase ABV by about 0.35. But it would only decrease the FG by roughly half a point, unless the yeast can suddenly eat the more complex sugars (doubtful) or dextrins (impossible) they previously left behind. I don't see how adding a bit of glucose is going to inspire the yeast to manufacture and use the transports/enzymes they need to handle the bigger stuff. Maybe I'm missing some mechanism you have in mind.

What about the (joking?) suggestion @Lizard made earlier about additing glucoamylase enzyme? It might not attack maltose (and the dextrose and glucose have already been metabolized) but it would get otherwise unfermentable dextrins and certainly dry things out.

Brooo Brother

 

[VikeMan]

What about the (joking?) suggestion @Lizard made earlier about additing glucoamylase enzyme? It might not attack maltose (and the dextrose and glucose have already been metabolized) but it would get otherwise unfermentable dextrins and certainly dry things out.

If wort fermentability was the issue, I'm sure it would have an impact.

 

[Brooothru]

If wort fermentability was the issue, I'm sure it would have an impact.

My thinking was that the LME is comprised of some unfermentable dextrins since it may only attenuate to <70%. Wouldn't glucoamylase break down these dextrins into fermentables available to the yeast, thus increasing the ABV and thinning the body, which appears to be the goal?

Brooo Brother

 

[VikeMan]

My thinking was that the LME is comprised of some unfermentable dextrins since it may only attenuate to >70%. Wouldn't glucoamylase break down these dextrins into fermentables available to the yeast, thus increasing the ABV and thinning the body, which appears to be the goal?

Yes. Well, all wort derived from a normal mash process has some unfermentable dextrins. But if a particular wort is very unfermentable, then glucoamylase should help.

 

[Kickass]

Call me a nihilist, but am I the only one here who would happily accept 1.034 on such a big beer? Sure, next time oxygenated your wort, but missing FG by .008 on such a big beer isn’t worth the hubbub, to me. Additionally, I wouldn’t be able to tell the difference between 1.034 and 1.026 and would venture I’m not the only one.

 

[Brooothru]

Call me a nihilist, but am I the only one here who would happily accept 1.034 on such a big beer? Sure, next time oxygenated your wort, but missing FG by .008 on such a big beer isn’t worth the hubbub, to me. Additionally, I wouldn’t be able to tell the difference between 1.034 and 1.026 and would venture I’m not the only one.

I think an additional 8 pts of attenuation would indeed be noticeable, especially in mouthfeel/body. Alcohol maybe not so much since it's already pretty high, but sweetness, maybe, even likely.

Brooo Brother

 

[VikeMan]

For snicks, I just popped the recipe and OP's OG into Brewcipher. It predicts an FG 0f 1.029. So, that's 3 points closer to the result than the expectation of 1.026 was.

 

[mcleanmj]

For snicks, I just popped the recipe and OP's OG into Brewcipher. It predicts an FG 0f 1.029. So, that's 3 points closer to the result than the expectation of 1.026 was.

I actually put the recipe into BrewCipher to check this yesterday (very useful software indeed). I didn't use the exact recipe from homebrewsupply. Since I usually mash at 1.5 quarts/gallon with BIAB, and for this batch I mashed in an 8.5 gallon kettle, I couldn't do the entire thing with over 25lbs of grains. So I did:

9 lbs 2-row
8 lbs LME
5 lbs munich malt
1.8 lbs roasted barley
1 lb chocolate malt
8 oz crystal 75 (couldn't get crystal 60)
4 oz black patent
1 lb table sugar

In other news - while the US-05 didn't have any impact on the forced fermentation sample, I pitched a full 5 gram package of champagne yeast into the 200 ml of wort, and it is fermenting. So, there are available sugars. Noble Grape replied by email and told me they indeed repackage Briess CBW light pilsen http://www.brewingwithbriess.com/Assets/PDFs/Briess_PISB_CBWPilsenLightLME.pdf
which has 76% fermentability. So, oxygenation seems to be the bigger problem.

I transferred the beer to a second vessel and pitched a well-oxygenated 1L starter (with 1/2 tsp White Labs yeast nutrient) onto the yeast cake. In about 10 hours I'll rack the beer back over it, stir it up and hope for the best. I would have pitched a 2L starter but didn't want to dilute the beer that much (that's 10% of the total batch size).

RE: just accepting the high FG. Normally I would, but I tasted it, and while it did taste very promising and delicious, its overly sweet and definitely needs to attenuate a bit more (if possible).

Cheers all and thanks for the lively thread!

 

[mcleanmj]

Hi folks

I just wanted to report that this approach seems to be working. 10 hours after I pitched the starter onto the yeast cake, there was a pretty thick krausen. I racked the beer back over and set it at 70 degrees. Nearly 24 hours later and its still slowly bubbling. Might try stirring it up today to keep yeast in suspension. Will check gravity in a couple days.

 

[smata67]

That's great. Yes, keep stirring it up while it is active, might get you a few more points. My revived krausens collapsed quicker than I'd ever seen. Checked on it, nice 2 inches thick, than two hours later, completely gone. As in no trace.

 

[IslandLizard]

Hi folks

I just wanted to report that this approach seems to be working. 10 hours after I pitched the starter onto the yeast cake, there was a pretty thick krausen. I racked the beer back over and set it at 70 degrees. Nearly 24 hours later and its still slowly bubbling. Might try stirring it up today to keep yeast in suspension. Will check gravity in a couple days.

Keep those fingers crossed.
To keep them engaged, keep the temps somewhat higher, say low 70s. And never let them drop, like they typically do overnight.

As mentioned before, Champagne yeast can only ferment glucose and dextrose, so any higher sugars such as maltose and maltotriose will remain, so hopefully the reactivated fermentation coaxes the original yeast back into action to take on that job. It's surely a complex mix of variables sugars and yeast.

 

[mcleanmj]

In summary, here's what I all tried:

Raised temperature to 72 degrees
Stirred up yeast 1-2 times per day
Pitched a cold-crashed, decanted 2-Liter starter of WLP001
Added yeast energizer
Transferred beer to a different vessel, pitched a 1-Liter starter wort onto the yeast cake, transferred the beer back at high krausen
Added 4 oz of corn sugar
Pitched an entire, actively fermenting 2-Liter starter of a different high-gravity yeast strain

None of this did anything, except the very last. Since pitching the starter yesterday, the gravity has come down by 1 point. Hoping for a couple more points, but not holding my breath.

I think I've exhausted all possible options. I am going to rack to 2ndary with bourbon and oak chips and let it age 3-6 months. I can only imagine how much oxygen I've put into this beer with all the stirring...

Maybe this will be useful for future brewers. In the future I would replace some extract with corn sugar, reduce the adjuncts, mash colder, and have a much lower target FG (like 1.020) so that missing by 5-6 points doesn't matter as much.

 

[mcleanmj]

In summary, here's what I all tried:

Raised temperature to 72 degrees
Stirred up yeast 1-2 times per day
Pitched a cold-crashed, decanted 2-Liter starter of WLP001
Added yeast energizer
Transferred beer to a different vessel, pitched a 1-Liter starter wort onto the yeast cake, transferred the beer back at high krausen
Added 4 oz of corn sugar
Pitched an entire, actively fermenting 2-Liter starter of a different high-gravity yeast strain

None of this did anything, except the very last. Since pitching the starter yesterday, the gravity has come down by 1 point. Hoping for a couple more points, but not holding my breath.

I think I've exhausted all possible options. I am going to rack to 2ndary with bourbon and oak chips and let it age 3-6 months. I can only imagine how much oxygen I've put into this beer with all the stirring...

Maybe this will be useful for future brewers. In the future I would replace some extract with corn sugar, reduce the adjuncts, mash colder, and have a much lower target FG (like 1.020) so that missing by 5-6 points doesn't matter as much.

Edit: down 2 points and I took a full hydrometer sample and drank it and it does taste amazing. Chocolatey, rich, roasted coffee, boozey (in a good way). Its thick and sweet, but it will definitely be OK.