Fermentation stopped

[moonlightelm]

I'm a beginner brewer. This is my 5th batch. I'm brewing sweet stout NB extract kit with the following ingredients:

0.5 lbs english chocolate malt
0.5 lbs weyermann carafa III malt
6 lbs amber malt syrup (half at 60 min/half at 15 min)
1 lb lactose
1 oz Williamette hops
Danstar Nottingham ale dry yeast

OG 1.053

After brewing, pitched yeast (72F) when wort was 78F. Wort sat in primary for 12 days at an average temperature of 65F. Racked to secondary and added 1 vanilla bean soaked in 1oz vodka and 3 cinnamon sticks. SG 1.030.

Wort has been in secondary for 8 weeks. First 3 weeks average temperature was 61F (in garage). Moved the carboy indoors where the average temperature has been 70F since. Air lock is still showing signs of fermentation (one leg elevated). Took SG today and it is still 1.030. This has me concerned that there was inadequate yeast in the wort.

Any thoughts on what I should do at this point?

 

[Calder]

1.030 seems high. Did you use an hydrometer or refractometer?

 

[moonlightelm]

Refractometer

 

[WissahickonBrew]

Some observations:

@ 61 degrees you kept the yeast at the lowest end of it's tolerance, that may be a factor...

Did you make a correction on your hydrometer readings for the temperature of the wort? This could move the dial a bit one way or the other...

 

[WissahickonBrew]

Refractometer readings are more accurate when you correct for temperature.

Refractometer

 

[Calder]

Refractometer

This is your problem. Refractometers read simple sugars in water. You now have alcohol which makes it extremely inaccurate. You are most likely closer to 1.015.

Find a refractometer conversion program and plug your numbers into that. It will give you a reasonable estimate of your FG. You will be able to find one on the web.

I don't use a refrac for FG as I have not yet gained enough confidence in the readings and conversion programs. I use an hydrometer every time ....... and I get to drink the sample.

 

[Calder]

Refractometer readings are more accurate when you correct for temperature.

Are you sure you are talking about a refractometer. This is not his problem.

 

[Jphillips13]

Did you use a correction chart for refractometer readings? Once alcohol is present the readings will be skewed. Even with correction I've read a refractometer isn't best to use after fermentation. Check it with a hydrometer. I bet it's a lot lower than you think and is probably done.
How does the beer taste?

 

[moonlightelm]

I just checked it with a hydrometer and got 1.022. still seems high?

 

[moonlightelm]

Tasted pretty good.

 

[moonlightelm]

I appreciate the tips on the refractometer. I got it as a gift for Christmas and this was my first time using it. Prior to that, I'd always used a hydrometer.

Do you think I'm ready for bottling at 1.022? That'll be a little over 4% abv by my calculation. Seems a little wimpy for a stout.

 

[Calder]

Lactose is unfermentable. 1 lb lactose will add .007 to both your OG and FG. If you take that off both, your beer went from 1.046 to 1.015, or 67% attenuation. Not great, but extract brews tend to end high, so probably done.

You are at 10 weeks, and tastes pretty good - it's done.

 

[moonlightelm]

Sounds great! Thanks for your input Calder. I'll let you know how it turns out in a couple weeks.