Just kegged my first batch of beer. Comments?

Wow, welcome to the hobby. Just curious what your mashing process was?

 

Also welcome! It's best to provide as much detail as possible: grain bill, mash temp, yeast details, fermentation temp, etc.

 

Hydrometer or refractometer for your gravity measurements?

 

Could be, but do you know any details about the yeast pack? Did you direct pitch and at what temp? Also do you know the date of the yeast?

 

Calibration is important, but it's probably not the major issue. Refractometer readings, both the OG and FG, but especially the FG need to be corrected using a refractometer calculator. You enter both brix readings together into the app or spreadsheet, and it gives you the corrected OG and FG. That little specific gravity scale on (probably) the right side of your refractometer display is a little inaccurate for OG and a lot inaccurate for FG. The two big reasons are that refractometers are scaled for use with sucrose solutions (which beer wort is mostly not) and because the presence of alcohol alters the reading.

ETA: If you didn't correct the readings, go ahead and do that and you'll probably see that your fermentation is actually finished.

 

@VikeMan is likely right if you didn't correct your FG refractometer reading with a calculator, but your yeast pitch rate was also low. I use the Brewer's Friend calculator which estimates your pitch rate at 0.17M cells/mL/°P. Complete ferments certainly can happen with underpitching, but I would use a starter for this type of beer.

 

Two packs is obviously much less of an underpitch. Your F.G. might be lower as mentioned above. FWIW I would never use 4 packs of liquid yeast - too pricey. Definitely look into starters!

 

Converting the gravities to Brix and plugging them into my favorite refractometer calculator, I get a corrected OG of 1.060, a corrected FG of 1.009, an apparent attenuation of 85%, and an ABV of 6.5%. Therefore I think we can call off the search for an explanation of the low degree of attenuation. The yeast may have been underpitched, the wort may have been underoxygenated, whatever, but 85% is not an unacceptably low degree of attenuation. Quite the opposite.

 

I think the FG issue was likely addressed by the refrac correction and the OG issue could be a combo of calibration of refrac and mash efficiency variance.

A philosophical word to the OP: when the numbers don’t add up, the first thing you might want to ask & answer is “How does it taste?”