Apparent stuck fermentation

[nefarious_1_]

This is my 2nd stuck fermentation in a row on JZ's Best Bitter recipe.

5gal. boil and topped up to 5.5gal. in fermenter.
(Recipe was modified from Jamil's method: a 7gal. boil down to 6 gal. with 5.5gal going into fermenter)

6.23lb Williams brewing liquid pale extract
0.46lb Aromatic
0.46lb Crystal 120L
0.23 Special Roast
1.14oz Kent Goldings 4.8% @ 60min.
0.31oz Kent Goldings 6.1% @ 20min. (I used left over hops which is why the additions seem strange)
0.08oz Kent Goldings 4.8% @ 20min.
0.50oz Kent Goldings 4.8% @ 1min.

Target OG 1.047
Target FG 1.012

Grains were steeped in 0.58gal. water @ 155*F for 30min. Sparged with 18oz 155* water.

Wort was cooled to 64*F within 15min. Aerated carboy by vigorously shaking for 2min.

Target OG was hit spot on @ 1.047!
Pitched 2L starter of WLP002 @ 64*F.

Temperature slowly rose to 68*F over 20 hours and remained at 68*F for the following 48 hours. At this point, vigorous fermentation was complete and the beer remained @ 68 - 69*F for an additional 7 days.
The following 1.5 weeks after that, the temperature remained between 66 and 68*F.

After successive gravity readings over the course of 4 days, it was determined FG = 1.022.

As stated earlier, this is the second time this has happened to me with this recipe. Each time my OG was spot on and I ended up with 1.022.

This is really bothering me because the last batch turned out waaaaaaay too sweet so I tried it again with no success!
I use WLP002 a lot and haven't had results like this. I've always had it finish down to at least 1.018, depending on the recipe.

Should I try pitching more yeast (different strain) or do you think it's the extract? This is my first time using Williams Brewing extract so I'm wondering if that's the issue...

Thoughts please?

 

[TheHomebrewConnection]

All yeast relies on a couple of things.
Strain of yeast
Physical Environment
temp, pH, density of liquid and head pressure
Nutrients and food
Oxygen
Good initial health

A stuck fermentation is usually caused by wort that is too rich in unfermentable carbohydrates. Lack of oxygen or nutrients can create a very slow fermentation. If you choose to add more yeast, make a starter and add it to your wort right after the yeasts lag time and as it begins to metabolize (get foamy), but beware of the foam that may result from co2 stuck in the wort. You can also use too much or too little yeast in the beginning of fermentation. They say 6 oz of yeast slurry with a chowder like consistency is ideal for 5 gallons of beer. If too much is originally pitched there wont be enough oxygen in the wort to sustain all that yeast.
I got these hits from Charlie Papazian's "The Brewer's Companion"

 

[nefarious_1_]

Well, I definitely did not overpitch. In fact, my pitching was exactly as called for by JZ in his book. Also, I find it hard to believe I extracted THAT much unfermentables during my steep, especially when my OG was spot on.

It's possible there wasn't enough oxygen, but I've never had a stuck fermentation before with my method (shaking for 2min.) Of course, there's a first time for everything, however the exact same thing happened twice in a row with the same recipe. Seems a little too coincidental IMO.

53% attenuation is downright awful.

Any other ideas?

 

[nefarious_1_]

Pitch some Nottingham?

 

[TheHomebrewConnection]

nottingham is some great stuff!

 

[JLem]

Might not be stuck. Could be a function of the ingredients you used. I don't know much about the brand of extract you used but some are more fermentable than others. Add to that a healthy charge of crystal and other specialty malts and you might end up with a rather unfermentable wort. When I was doing extract based beers I would often finish at 1.020.

 

[nefarious_1_]

Might not be stuck. Could be a function of the ingredients you used. I don't know much about the brand of extract you used but some are more fermentable than others. Add to that a healthy charge of crystal and other specialty malts and you might end up with a rather unfermentable wort. When I was doing extract based beers I would often finish at 1.020.

I would like to think there's nothing wrong with JZ's recipe, which leads me to believe the problem is the extract or yeast.

I guess it's possible the wort was only 53% fermentable, but it seems rather unlikely to me. I do find it interesting that the exact same thing occurred twice in a row under almost identical conditions.

I really don't want to dump this batch, but I'm considering it at this point...
If it's the extract, pitching more yeast obviously wouldn't help. But I guess it wouldn't hurt just to see?

 

[SwampassJ]

I would like to think there's nothing wrong with JZ's recipe, which leads me to believe the problem is the extract or yeast.

I guess it's possible the wort was only 53% fermentable, but it seems rather unlikely to me. I do find it interesting that the exact same thing occurred twice in a row under almost identical conditions.

I really don't want to dump this batch, but I'm considering it at this point...
If it's the extract, pitching more yeast obviously wouldn't help. But I guess it wouldn't hurt just to see?

If it's absolutely undrinkably sweet/thick toss in some Nottingham. I don't care for it's flavor profile but it will eat almost anything. I can't find the thread now but there is a large English yeast thread talking about how fickle 002/1968 is and likes to settle. They suggest swirling/agitating the yeast back into suspension (I've done this with 005 and it worked) or adding some sugar directly to the boil (I did this with my last batch of 002 with a 154 mash temp and decent amount of crystal) and I got it to go from 1.048 to 1.012.

 

[nefarious_1_]

Thanks for the replies.

Yea, I've heard about warming the beer a little and rousing 002 to improve attenuation, but I've never had to do it. I'm going to give that a shot before I pitch the Nottingham.

I'm not expecting to get down to the target 1.012, but at least 5 more gravity points would be nice seeing how the last batch tastes like crap to me (my friend drinks it) and I'm on the verge of dumping this one.

Keeping my fingers crossed and hoping for the best.

 

[IffyG]

When I was doing extract based beers I would often finish at 1.020.

This was also my experience. Most of my LME based beers stopped at 1.020 and with DME I was lucky to see 1.016.