White Labs - high FG?

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bredstein

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Liquid yest gurus, please help! After about twenty successful (to my taste) brews with dry yeast, I decided to try the liquid form. It was an AG Double Chocolate Stout, The yeast is WL London Ale 013. It came to me by mail, the ice pack melted of course. I made a starter with DME, and although it didn't look active, the smell was good, and when I pitched it, the fermantation started within 12 hours, and was bubbling nicely for two of three days, then slowed down. The FG dropped from .058 to .017, and stayed at this level for three days. So I decided to bottle the beer.

Now my question is - why did I end with such a high gravity? According to the instructions, I should have gotten somewhere close to .012. I did not make any changes to mash, boiling, etc., and every time I used dry yeast, I was much closer to the target FG. So the only thing different is liquid yeast, and I am trying to understand what went wrong. On the other hand, maybe it is not a big deal, 17 vs 12?
 
Liquid yest gurus, please help! After about twenty successful (to my taste) brews with dry yeast, I decided to try the liquid form. It was an AG Double Chocolate Stout, The yeast is WL London Ale 013. It came to me by mail, the ice pack melted of course. I made a starter with DME, and although it didn't look active, the smell was good, and when I pitched it, the fermantation started within 12 hours, and was bubbling nicely for two of three days, then slowed down. The FG dropped from .058 to .017, and stayed at this level for three days. So I decided to bottle the beer.

Now my question is - why did I end with such a high gravity? According to the instructions, I should have gotten somewhere close to .012. I did not make any changes to mash, boiling, etc., and every time I used dry yeast, I was much closer to the target FG. So the only thing different is liquid yeast, and I am trying to understand what went wrong. On the other hand, maybe it is not a big deal, 17 vs 12?


1.017 is a perfectly reasonable FG for a chocolate stout.

Attenuation depends on recipe ingredients, mash temperature, and yeast strain. I don't know why your instructions picked 1.012 for the FG, but I have an oatmeal stout right now that finished at 1.020. And it's great.
 
fwiw, left unmentioned is the amount of viable yeast pitched and it's rather significant effect on attenuation.

And according to MrMalty's Yeast Pitching Calculator, even if your vial of yeast magically ended up in your hands the same day the yeast was cultured, you'd still need two vials to reach an optimum pitch rate with a five gallon batch with an OG of 1.058.

Put some time and perhaps warm transport on the clock - let's say that vial was the equivalent of two months old - and the underpitch was more like 1/3 of optimal...

Cheers!
 
Put some time and perhaps warm transport on the clock - let's say that vial was the equivalent of two months old - and the underpitch was more like 1/3 of optimal...

I believe my starter took care of that? And as I mentioned, the FG stabilized for the past few days. What do you think?
 
I believe my starter took care of that? And as I mentioned, the FG stabilized for the past few days. What do you think?

Depends. It wasn't clear the starter was very active from your description, might still have been short on cells when you pitched. As for the stabile SG, you'll eventually get to that point whether over/under/perfect pitch, it's the final number and how it resulted that's interesting.

btw, I don't disagree that your current SG is out of bounds for a nice stout - they can support a fairly sweet finish unlike most styles. Should be plenty enjoyable..

Cheers!
 
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