Low Alcohol after fermentation should I re-pitch?

[Downey26]

I brewed four beers and when I went to keg them I checked the final gravity. I found I had lazy yeast and my ABV was too low. For example my IPA OG was 1.068 after 7 days of fermentation and 3 days of dry hop my final gravity was 1.032, leaving me an ABV of 4.7%. This beer should have a ABV of about 8%.
I did not use any oxygen when I placed it into the carboy because I was out of oxygen canisters. I imagine this is why my yeast didn't react the way it should.

The bad thing is I have already cooled the beer to keg it. Can I raise the beer temp back up to 68 degrees again and re-pitch the yeast in order to get a higher ABV? Should I use a Fermaid K? Am I stuck with a low ABV beer?

 

[Calder]

Did you use an hydrometer or a refractometer?

 

[Yooper]

I brewed four beers and when I went to keg them I checked the final gravity. I found I had lazy yeast and my ABV was too low. For example my IPA OG was 1.068 after 7 days of fermentation and 3 days of dry hop my final gravity was 1.032, leaving me an ABV of 4.7%. This beer should have a ABV of about 8%.
I did not use any oxygen when I placed it into the carboy because I was out of oxygen canisters. I imagine this is why my yeast didn't react the way it should.

The bad thing is I have already cooled the beer to keg it. Can I raise the beer temp back up to 68 degrees again and re-pitch the yeast in order to get a higher ABV? Should I use a Fermaid K? Am I stuck with a low ABV beer?

Even without oxygen, the attenuation should have been better than that, depending on yeast strain. If you used a refractometer to take the FG, make sure to take another reading with a hydrometer as refractometers results are skewed by alcohol and are inaccurate.

how does the beer taste? Does it taste like it's not fermented out, and hazy with yeast? If it tastes good, and not half-fermented, I'd leave it be regardless of the actual FG reading.

If the reading of 1.032 was via hydrometer and if the beer is undrinkable as is, then it would be possible to bring it back to room temperature and it may start fermenting again even without repitching.

It doesn't seem like 1.032 could be a likely reading after 7 days of active fermentation, though, so I do suspect a faulty reading.

 

[Downey26]

I used a refractometer. The beer tastes good. I was unaware the alcohol gives it a faulty reading. I will use my Hydrometer and get an additional reading. Thanks for the helps guys.

 

[Yooper]

I used a refractometer. The beer tastes good. I was unaware the alcohol gives it a faulty reading. I will use my Hydrometer and get an additional reading. Thanks for the helps guys.

You can run it through a correction table, and that is better than not doing it, but I've never had one be 100% accurate. This one is the best I've found, though: http://seanterrill.com/2012/01/06/refractometer-calculator/