WLP833 in Oktoberfest and Classic American Pilsner

[Good Ed]

I brewed 23L of Oktoberfest and Classic American Pilsner 2 weeks ago, used a 4L starter of WLP833 in each and they have been fermenting at 11-12C. I tested the SG last night and the Oktoberfest has gone from 1056 to 1034 and the CAP from 1061 to 1041. They both started off with a good ferment within 24 hours, but the airlock activity has stopped on the Oktoberfest and is very slow on the CAP. There were surface bubbles on about 3/4 of the surface of the FV but no head per se. I'm not in any hurry with these but also I don't want them finishing way high, I'm aiming for 1014/1015.

The question is, can I do anything? should I rouse them? or increase the temperature a couple of degrees? any advise would be appreciated.

 

[pittsy]

12c is ideal , it (they )do seem slow , you could try adding yeast nutrient and giving them both a good stir (no splashing) and just a waiting game id leave temp as is ,how long did you give the starters before using and did you do around 200g DME with around a litre of water in each starter

 

[Good Ed]

Thanks pittsy, I don't think ther was a problem with the starters I always use 100g DME per 1L water, stepped these up over 2 weeks finally with 4L and 400g of DME for each. Checked again today and they have both dropped a couple of points over the last 2 days and there is a head on the Okoberfest after me giving it a stir. I'm going to add some yeast nutrient and wait it out, hopefully with good results.

 

[Mark1964]

have you given a diecetyl rest for the pilsners it may help with fermentation as it involved raising the temp of the fvs to around 16 degrees for 2 or 3 days then taking the temp back to 12 degrees we found when we raised the temp fermentation speeded up again. Also by doing that your beer wont have any off flavours when finished

 

[Good Ed]

Thanks Mark, I'll give that a try, although with this yeast I don't usually have any problems with diacetyl

 

[Good Ed]

Well after 5 1/2 weeks the Oktoberfest is down to 1011 and will be bottled tonight, the CAP is a few days behind. No off flavours present . I raised the temperature to 15C for a week before dropping down to 12C; it's just taken a long time. I can only think that the viability of the yeast wasn't good even though they both had 4L starters, and I'll be buying some fresh WLP833 next time.