Here's my situation, I started my first batch 71 hours ago and have yet to see any real activity. There are these tiny bubbles that gather in the airlock, but nothing that really makes me think that there's fermentation taking place in there. I haven't been able to make it back down to the brew shop for some more yeast to throw in there, so I started thinking about it. Temperature has been good and steady. There is quite a bit of head space in there, about a gallon and a half worth. Could that be my problem? Anyone have any similar experiences? Also, at what point is it too late to throw more yeast in the primary? For my innaugural batch I figured it would probably be best to play it simple and brew from a kit, it's a Woodforde bitter kit, if that's of any consequence. I'm really trying to be patient and not crack it open and ask "you guys doing okay in there?" What do y'all think?