I spent all last week stepping up a kolsch starter, brewed today with a nice-looking pitch ready to go. While chilling the wort, I decanted the starter wort, and added about a pint of the fresh kolsch wort to wake the yeast up. I saw a lot of activity within a half hour or so - it was really foaming up! I was about to pitch it, and took off the foil to find that it smelled sour. Kind of lactic to me. I poured a sample, and it was hard to tell because I was tasting the fresh sweet wort along with yeast and a mild carbonation from the activity. But it really seemed to have a tang, so I dumped it.
Now I’ll have to wait until tomorrow to get a smack pack from the LHBS. I am planning to have my wife pick it up and smack it in the morning, and pitch when I get home from work in the afternoon. That will be about 24 hours from chill to pitch. I’m nervous!