This is my first time using WY3068 Weihenstephan Wheat. I brewed the NB Dunkelweizen kit on 9/13 using this yeast. I smacked the pack earlier in the day and it was fully expanded by the time I pitched the yeast - I did not brew up a starter for this batch. OG was ~1.054. I substituted 2lbs of golden DME for some of the wheat LME because the kit shipped with the wrong ingredients and I did not realize this until after I started to brew.
I put the carboy in my basement and let it ferment through. Temp was ~64-66 degrees. It had a nice krausen and then fell back into the beer after a couple of days. On 9/27, I racked the beer to a secondary fermenter and sealed with an airlock. Within hours, a thin layer of krausen formed on the surface of the beer and bubbles began pushing through the airlock again. I moved the beer from the basement to my third floor where the beer temp is more around 68-70 degrees. Now, almost three weeks after brew day, the beer is still showing signs of active fermentation. I did not take a gravity reading when I racked the beer, nor did I taste the beer at that time. The beer smells good.
So, my question is, should I be concerned with the fact that this beer is still actively fermenting? I consulted with a few of my homebrewing friends and the only plausible explanation we can think of is that fermentation became stuck, likely due to low temperature and/or low pitch rate, and that fermentation was kick started again when the beer was agitated during the racking process. Bacterial infection is possible, but doesn’t seem likely given a thorough cleaning process during racking and the fact that the beer doesn’t exhibit any off aromas (don’t know about flavors yet).
Any thoughts on these events or your experiences using this yeast strain are appreciated. Thanks.