Very low FG

[Mgb714]

I have a very low FG reading and trying to figure out what I did wrong.

Disclaimer: completely new at this so I have no idea what I'm doing. Ive done a few 1 gallon AG kits from Brooklyn before and decided to strike out on my own. At the risk of sounding silly, here's what I did:

1 gallon Chocolate Raisin Stout BIAB

2.1 lbs 2-row
0.11 lb special b
0.11 lb chocolate malt
0.11 lb rolled oats
0.6 oz roasted barley

0.15 oz cascade @ 90m
0.15 oz cascade @ 30m
1/2 tsp Irish moss @20m
0.15 oz cascade @ 0m
0.4 oz Monukka raisins @ 0m
0.4 oz organic cacao nibs in primary

Safale-05 yeast

Mash @ 150°F for 60m
Boil for 90m
Pitched at 60°F

Expected OG: 1.069
Actual OG: 1.062 (refractometer)

Expected OG: 1.017
Actual FG: 1.005 (refractometer)

Mash temp was right on. Used a Grainfather with 2 gallons of tap water (had it tested, it's a decent water profile). Did a BIAB because of the low grain bill limitations of the Grainfather. Fermenting in a Brew Demon 2.5 gallon conical fermenter submerged in a 50°F waterbath.

Anyone see something I did wrong? Really trying to make this a serious hobby and want to get better.

 

[khillian]

Did you pitch the whole 11g packet of US05? Using yeast calculators you needed 4-5 grams for that OG/Batch size. Over pitching will drive attenuation causing lower final gravity. Might also shoot for 152F mash temp next time.

 

[WrQth]

Once alcohol is present the reading on a refractometer is not accurate without correction. There are many available but I've used BrewersFriend's

http://www.brewersfriend.com/refractometer-calculator/

 

[schatzke]

you need a hydrometer to test for FG. or did you take the number from your refractometer and do a conversion?

 

[Mgb714]

Thanks everyone for the replies!

The FG was done without a conversion on the refractometer. Per the website link WrQth gave, the converted FG is 0.988. However, I absolutely threw in the entire 11g packet, didn't bother to calculate how much yeast I needed. So the next question, is this beer drinkable?

 

[Amadeo38]

I suspect that measurement is still inaccurate even with the conversion. You really need a hydrometer for FG when alcohol is present. I think it's pretty rare to see FG drop below 1.000 with s-05 regardless of how much you pitch.

 

[Mgb714]

Adding hydrometer to my list of equipment upgrades for sure.