Long Primary Fermination

I am brewing a Baltic Porter using the NB kit and California Yeast. It has been in the primary for almost 4 weeks and I am still seeing activity. For the first 3 weeks it was in my basement at 54 degrees. Thought the temperature was a little low so I moved it to a closest at 68 degrees. Thought this would help, but it is still going. Anyone have any experiences like this?

Take a gravity reading today, wait a couple of days and take another, see if there’s really anything going on. It’s quite possible that the higher temp is forcing CO2 out of solution rather than any actual yeast activity.

What was the OG of the beer, and how much yeast did you pitch? That yeast shouldn’t take that long, but if you underpitched, combined with the low temperature that could explain the long time frame. Take Shadetree’s advice also; it could just be CO2 releasing from the higher temperature.

I should have said that it has been the 68 degree closet for about a week now. I did see the increase like you said the first couple of days, but since then it has decreased. Just doesn’t seem to want to finish up. Is it possible to still have some foam on the top if primary fermentation is complete?

OG was 1.074. I made 2000ml starter with 1.5 cups of extract from a pint of yeast I rinsed from a California Common I made two months ago.

Sounds like you had enough yeast, and yes you can still see foam on the top even after it has finished fermenting. Take the gravity readings and if you get the same reading three days in a row, it’s done.

Current gravity is still a little high. 1.029.

[quote=“mak”]Current gravity is still a little high. 1.029.[/quote]Give the carboy a good swirl, see if you can get the yeast to rouse. If not, use a long spoon and gently stir to break up the cake and get it back in suspension.

How fermentable was the wort? If you used a higher temperature mash, 1.029 may be done.

It is an extract brew. Estimated final gravity is 1.016

[quote=“mak”]It is an extract brew. Estimated final gravity is 1.016[/quote]The estimate is a calculated number based on the attenuation range from the manufacturer, and that range is itself based on in-house tests with a specific wort. So it’s not intended to be used to project your particular FG, since they have no idea what is in your wort, but instead it is used to compare one yeast against another from the same manufacturer.

1.016 is pretty low for an extract kit with an OG of 1.074. Did the kit include some sugar to add as well as malt? If not, then I wouldn’t expect it to go much below 1.020 best case. Regardless, 1.029 is probably not yet done. Use a sanitized tool to stir up the yeast from the bottom as Shadetree suggested and keep it in the 68F room. Then just see what happens.

Thanks everyone for your help. It is down to 1.023.