Marzen Slow Fermentation HELP

[seabeemech1970]

I brewed up a batch of Märzen Bier this past Sunday, OG 1.047. I pitched (2) vials of WLP820 Oktoberfest/Märzen Lager Yeast. My fermentation chamber is set to 55F. Which is midrange of the optimum for this yeast. It been going on 36 hours as of this morning and still no active fermentation. I gave it a lot of oxygen, used a electric drill and stirring attachment for 5 minutes. Am I just being too nervous or what?

 

[slarkin712]

Give it a little more time. Lager fermentations generally take longer to get going than ales. If this is a 5 gallon batch I'd say that you underpitched the amount of yeast needed, but you'll be OK.

 

[TyTanium]

If this is a 5 gallon batch I'd say that you underpitched the amount of yeast needed, but you'll be OK.

+1 for underpitch. Check out this calculator: http://yeastcalc.com/

For 5g at 1047, you need over 300bn cells. You probably pitched closer to 150, 200 max. You can let it warm a little (like 58 or so) until you see krausen, then slowly drop it back down.

 

[seabeemech1970]

+1 for underpitch. Check out this calculator: http://yeastcalc.com/

For 5g at 1047, you need over 300bn cells. You probably pitched closer to 150, 200 max. You can let it warm a little (like 58 or so) until you see krausen, then slowly drop it back down.

Ok its been 8 days. I took a reading its at 1.038 down from 1.047. So whats the best thing to do now? Just wait and keep hoping that the yeast will take off?

 

[slarkin712]

If you've still got a layer of krausen then it's going to keep going. If the kraussen has dropped then I'm not sure that you'll get to a low FG. I'd definitely let it go for another week and see where it is. I think you'll probably be OK, just be patient.

 

[ContinuousD]

Give it some time. 820 is really slow. There are many posts here about 820 and it being slow. White Labs also says the same:
http://www.whitelabs.com/beer/strains_wlp820.html
I have done a couple of 10 gallon Marzen split batches this year, both times using 820 in half and Saflager S-23 in the other half. In both cases the S-23 was done about 2 weeks ahead of the 820.
I fermented all of them around 52 degrees. The 820 finished 1 point higher both times, 1.015/1.014. So far the 820 tastes a little cleaner, the S-23 a little richer. I actually prefer the S-23 so far but will not pick between the 2 for another month or so.

 

[seabeemech1970]

If you've still got a layer of krausen then it's going to keep going. If the kraussen has dropped then I'm not sure that you'll get to a low FG. I'd definitely let it go for another week and see where it is. I think you'll probably be OK, just be patient.

I still have a krausen going. although as i watch it see chucks of the krausen falling. along the sides of the carboy there is a almost like yeast scaling? I've attached a couple pics, let me know what you think.