My California Common is still bubbling at a rate of about once every 20 sec. and it's been 11 days since I pitched the yeast. It takes two ice changes a day to keep the temp below 62*. I want to brew another ale, but am worried about the temp in my water bath going up too high for the SF Lager Yeast. How long do I need to keep the temp below 64* for this yeast?