stalled fermentation

[natebanks7]

I recently brewed an extract lager with an OG of 1.079. My LHBS suggested m aking a starter from dry yeast to get the cell count up and it seemed to go well and fermented for a couple of weeks. I tested it and it was 1.024 so I did a d-rest for 36 hours then chilled to 42* to lager. I was hoping to see the gravity go down more but after 4 weeks lagering it is still at 1.024 d it is tasting very sweet. My question is ther anything I can do to ferment this farther without risking the batch? My plan was to lager this for about 4 more months before bottling. Thanks

 

[pdxal]

We need more information to work from. How about the full recipe, method for making the starter, and type of yeast.
If there are more fermentable sugars present, you could warm the beer back up and see if the yeast will pick back up. If no fermentable sugars are left (which is likely with an extract beer) nothing will make it ferment down farther short of amylase.

 

[Cyclman]

Beer does not significantly ferment when lagering, it is too cold for very much yeast activity at all.

Bring it back up to d-rest temps, don't cool it until it hits FG for 3+ days.

 

[natebanks7]

6.6 lbs amber lme
3 lbs amber dme
.75 lbs carafa I
.25 lbs black patent
1 oz tettnanger (60 min)
1 oz Kent golding (30 min)
11.5 g W34/70

I made a starter with 1 quart water and 1 cup xlite dme a nd let it ferment for about 3 days at 60* till it was done, cold crashed and Decanted, added to 60* wort started fermenting within 4 hours and I let it go for 3 weeks at 54*. Tested It and it was at 1.024. Bumped it up to 65* for d- rest for 3 days and transfered to secondary for about 4 weeks at 42* but had to bump it up to ferment another lager. I tested it again when brewing new lager and still at1.024. Would there be any benefit to sprinkling a little more dry yeast and swirling it up? I am planning on keeping it with new lager through d-rest too.

 

[pdxal]

There's a lot of unfermentables in that recipe (DME and LME have a proportion of crystal in them, carafa and black patent will be 6-7 points of gravity that won't ferment too). As mentioned, warm it up, but it might not dry out any more. More dry yeast likely wouldn't do it, but an active starter at high krausen would be what you add to help.

 

[natebanks7]

Wouldn't I have to worry about extra O2 going into my mostly fermented beer? Howbig a starter should I use? And u say I should pitch it while still fermenting? Thanks for all the help.

 

[natebanks7]

Also should I re-rack it to another carboy when its done since I am planning on leaving it in ther for a few more months?

 

[pdxal]

If you do anything to the beer you have to worry about oxidation, that includes transferring to another carboy.
To restart a stuck fermentation you want a starter at high krausen, not a package of yeast. If the fermentation restarts it will scrub the oxygen as a part of fermentation.
I wouldn't do anything to it except warm it up and hope it finishes lower. You can lager on the yeast cake, it won't hurt it but transferring might.
Warm it up for a week, then lager it another 4 weeks or so and call it done.

 

[natebanks7]

I swirled the carboy around in a milk crate without taking off the airlock to resuspend the yeast and turned up thetemp a bit and I will check it again in a few days. Thanks for the advice