I bought a extract kit from Northern Brewer which included a Wyeast activator pack (smack pack) London 1028. I actually activated the package a week ago and had some things come up so I didn't actually use the yeast until last night. I didn't see any activity in my fermenter this morning so I was a little concerned that the yeast may have died or something due to the long wait. The pack inflated within 8 hours after I activated it last week. What's the longest someone should wait to use the Wyeast activator packs after they've expanded? If I don't see any activity in the next day I'm going to add some dry ale yeast.