I made a yeast starter for an IPA that I am going to brew, but the yeast (WLP001) is old. The expiration date on it is April, 08. It has been a day and a half now and I still don't see any activity with the yeast. Is it completely dead and should I just go buy some fresh yeast? Also, if it does come to life, would old yeast give the beer and bad or off flavors?