Lager krausen won't fall

Question

I'm brewing my first true lager with White Labs WLP800 and the krausen won't fall. I'm being somewhat impatient because it's taking up primary space right now. I pitched at 44°f and let it rise to 50°f over the first two days and have kept it there since. It has now been 14 days and the krausen is still about an inch thick and the bubbling has slowed to once every 30 seconds. Also I pitched a decanted 4 liter 2 vial starter and oxygenated the wort really well.

I hate taking gravity readings until I'm ready to move to secondary, but is this pace normal for a lager? If so, can I speed it up by bringing up the temperature by 10° or so like a rest, or would it be unnecessary since I have kept it low the whole time?

Answer 1

I'm sure you know this, but impatience and lagers are not a good match! I just did a lager with the same yeast strain, and it took at least two weeks at 50F, 10C for the krausen to fall, and was bubbling for 3 weeks. This pace is pretty normal for a lager.

I would leave it for a few more days, and then raise to 60-64F for a diacetyl rest for 48h before racking to secondary and lagering. You can take a sample from primary before and after the rest, both for the gravity and as a taste comparison. For me, exposure to oxygen is a bigger concern than contamination. When you take a sample before the rest, any oxygen in the headspace will be pushed out as the CO2 expands with the temperature increase, and as more CO2 is produced with increased yeast activity. When racking to secondary, the amount of oxygen expsure is also limited since the next of the carboy is very small.

Answer 2

It sounds normal to me. I normally leave my primaries for a month or so. Purchase a new primary if its a problem or plan better.