why is my beer not finishing?

I brewed the "hoppiness is an IPA" recipe from brewing classic styles 3 weeks ago.
the grain bill is as follows
1lb crystal 15l
.25lb crystal 40l
9.75 lbs of light LME
.5 lbs of Munich LME

the recipe states the og should be 1.065 (I got 1.066) and the FG should be 1.012.
I fermented at the suggested 67 degrees and used a 1.6L stirred starter.
SO my question is, why is my fg only at 1.020 3 weeks later? I took a reading last saturday, gently rocked the carboy and raised the temp to 72 degrees. It has been sitting at 72 since saturday and I took another reading just now and it is still at 1.020.
please help

It is not too uncommon for some extract beers to finish high. Pretty much all of my extract brews with or without starters still finished around 1.020.

I also bottled every one of them with no issues.

did you use and oxygen stone or some way of airating the wort prior to piching the yeast? That would be the first thing I would look at.

Deuce said:

did you use and oxygen stone or some way of airating the wort prior to piching the yeast? That would be the first thing I would look at.

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no, I have been meaning to buy a system. I did stir the wort splashing a bunch and shaking the carboy before i pitched the yeast. Fermentation started within 12 hours and took off pretty strong creating about a 3-4 inch krausen.

McKBrew said:

It is not too uncommon for some extract beers to finish high. Pretty much all of my extract brews with or without starters still finished around 1.020.

I also bottled every one of them with no issues.

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my last two extract beers have been 1.017 and 1.018

Could be your hydrometer.. I had checked my hydrometer against my water, and it registered perfectly.. Problem occurs that I get my water from my outside tap so it is not softened. Unknown to me is that my softened water comes out at a nice 1.000, but my water from the tap comes out at 1.002. Several beers seemed to finish high, but after I figured this out, no problems.

chemman14 said:

my last two extract beers have been 1.017 and 1.018

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My last 2 beers started at 1.062 and 1.050 and they both finished at 1.010, one with a 700mL starter and the other was pitched onto a yeast cake.

I was going to say get it warmer and try to swirl the yeast a bit.
Then I actually read your post and see you did just that.
It seems that 1.020 is where your beer wants to be. It could be the brand of extract used, yeast strain, or initial oxygenation. Did you do anything different this batch?

But I forgot to add I got lucky I believe!

barely said:

I was going to say get it warmer and try to swirl the yeast a bit.
Then I actually read your post and see you did just that.
It seems that 1.020 is where your beer wants to be. It could be the brand of extract used, yeast strain, or initial oxygenation. Did you do anything different this batch?

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new extract supplier because I moved but seemed like good quality extract stored in co2 pressurized barrels

just tested my hydrometer in water and it read 1.000 @ 75
so this means it is actually 1.002
so that means my brew may actually be at 1.018, still a little high and the sample tasted slightly sweet(its so hard to diagnose the taste of green beer)
maybe its time to get a refractometer

Some brands of extract ferment out much more than others. If you stick with the same brand, you should get consistent results.
According to Ray Daniels Designing Great Beers, with a selection of extracts that he had tested, the fermentability of the extracts varied from 44.4% to 64.1%
If you want to end up with a lower FG, you may want to change the brand of extract you are using, but I'd certainly do a taste test first.

-a.

ajf said:

Some brands of extract ferment out much more than others. If you stick with the same brand, you should get consistent results.
According to Ray Daniels Designing Great Beers, with a selection of extracts that he had tested, the fermentability of the extracts varied from 44.4% to 64.1%
If you want to end up with a lower FG, you may want to change the brand of extract you are using, but I'd certainly do a taste test first.

-a.

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I don't really have a choice as that is the only shop in the area

so is there a chance is an aeration issue?