My IPA has stopped at 1.022. Can I add dextrose to “wake up” the yeast?

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Torrefaction

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Hey folks,

Here’s the goods (see recipe below): mashed at 154 F (68 C), aerated by pouring from bucket to bucket a few times. I pitched one vial of WLP001 plus a vial of WLP007; I had both on hand, didn’t have time to make a starter before brew day, and thought it would be fun to try (since I like both yeasts and read there's really no downside). Both vials were super fresh (one week). Started at 64-ish, let it climb to 68, been hanging out there about a week now. Had massive krausen forever (a week?) and had to use a blowoff tube three days into fermentation.

Took my FG today, and after two weeks it’s at 1.022. There’s been airlock activity pretty much the whole time (slow, of course, like one bubble a minute), so the yeast could still be munching (I’ve heard of 007 taking its time), but that seems a bit high to me given the two vials and the grain bill, plus the two weeks in the carboy (primary only).

I’ve started swirling to see what that gets me. If I don’t see results in a couple of days, I’m considering this, which I found (on homebrewtalk) after some googlin’:

1.) Dissolve 3 oz of corn or table sugar along with some yeast nutrient in boiling water, cool it down to fermentation temperature and add this mixture *gently* to your fermenter (avoid splashing). Sucrose and dextrose are very easy for yeast to ferment, and adding some along with yeast nutrients can provide the yeast with just enough of a boost to resume fermentation of more complex sugars remaining in your wort.

Is this legit? Any risks?

The hydro sample tasted great, by the way; not too sweet at all, but it’s “heavy” in the mouth like a barley wine. If I do nothing, I’ll still have a beer I’m happy with, so I’ll hold off on the dextrose if there’s any risk of things going funny. Note: I bottle-carb with dextrose, so one concern I have is over-priming: was planning to bottle in about a week.

Appreciate any input—thanks! :mug:


Chestburster IPA
Method: All Grain
Style: American IPA
Boil Time: 60 min
Batch Size: 20 liters (fermentor volume)
Boil Size: 28 liters
Boil Gravity: 1.050 (recipe based estimate)
Efficiency: 71% (brew house)

Original Gravity:
1.070
Final Gravity:
1.015
ABV (standard):
7.24%
IBU (tinseth):
110.96
SRM (morey):
6.1
Fermentables
Amount Fermentable PPG °L Bill %
5.7 kg Canadian - Pale 2-Row 36 1.75 86%
0.7 kg Canadian - Munich Light 34 10 10.6%
0.125 kg German - CaraHell 34 11 1.9%
0.1 kg German - Acidulated Malt 27 3.4 1.5%
6.63 kg Total
Hops
Amount Variety Type AA Use Time IBU
15 g Warrior Pellet 16 First Wort 18.45
15 g Warrior Pellet 16 Boil 60 min 30.47
25 g Centennial Pellet 10 Boil 15 min 15.75
25 g Chinook Leaf/Whole 13 Boil 10 min 13.6
25 g Citra Pellet 13.4 Boil 10 min 15.42
25 g Nugget Pellet 15 Boil 10 min 17.26
25 g Centennial Pellet 10 Whirlpool at °C 20 min
25 g Chinook Leaf/Whole 13 Whirlpool at °C 20 min
25 g Citra Pellet 13.4 Whirlpool at °C 20 min
50 g Nugget Pellet 15 Whirlpool at °C 20 min
50 g Centennial Pellet 10 Dry Hop 5 days
50 g Citra Pellet 13.4 Dry Hop 5 days
25 g Nugget Pellet 15 Dry Hop 5 days

Yeast
White Labs - California Ale Yeast WLP001
White Labs - Dry English Ale Yeast WLP007
 
Did you use a refractometer to take the gravity readings, or a hydrometer?
 
To answer your question, No it wouldn't hurt. Might it help? Maybe not, because if she's done, then that's it. The 154* mash temp might have yielded a few too many unfermentable dextrans.
But, if you are unsatisfied , then by all means add the nutrients and the sugar, give the bucket a swirl to rouse the yeast, and warm it up to 70. In other words, go full bore.
boydster's Q is a good one, because if you used a refractometer, make sure you did the calculations to compensate or your reading will be high.
 
By the way, with an OG of 1.070, 2 vials will be an underpitch. I didn't look it up in Mr. Malty, but I believe you probably needed somewhere in the neighborhood of 300-350billion cells. Two vials at their freshest will only give you 200b. Critical? No, but it probably contributed to the issue.
 
Thanks! I used a hydrometer, so it's not the reading. Yeah, I was thinking I mashed a little high. Probably should have shot for 149, especially with that 1.070 OG.
 
And thanks for pointing out the underpitch; wouldn't have even thought of that, because, hey, two vials. Would there be any point to throwing in some US-05 at this point?
 
Adding honey or sugar can possibly kickstart it again if it's truly stuck and won't start up other ways. If you check it in a few days and it's still 1.022, then it's very possible that your mash temp was higher than you thought, and the beer is finished. Have you calibrated your thermometer lately? Example, a mash temp of 154F vs 156F can mean a lot of difference in how much is fermentable. Let us know how it's going.
 
And thanks for pointing out the underpitch; wouldn't have even thought of that, because, hey, two vials. Would there be any point to throwing in some US-05 at this point?

Nope, too late. At this point if you wanted to add more yeast, in order to overcome the low pH and high alcohol, you'd have to go BIG- create a big starter and pitch it at the point of high krausen.
 
I use an old analog thermometer, and truth be told I don't know how accurate it is; I think a good digital one will be my next upgrade (any suggestions? already returned two duds). Seeing as the beer tastes great and is already at 6.3% ABV, I think I'll just watch it and bottle in a week or so after taking a second gravity reading. I'll save the 'full bore' approach for a beer with actual problems. Thanks for the input!
 
The final product is sweet--too sweet, which is surprising and disappointing given that the samples really weren't. Bummer! I bought a new digital thermometer (lavatools javelin) to correct mash temps. If this were to happen again I'd do something drastic to get my FG under 1018 or so: amylase, beano, etc... but of course this won't happen again ;). Thanks for the input!
 
Post script: this ended up being perhaps my favorite ale yet; the body and juiciness complemented the tropical hops (tons of late citra and nugget) really nicely. So for newbs perusing threads on knocking down a high fg because of mash temps, you may want to ride it out. Cheers.
 
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