Just wanted to share my experience with sour crop, in case anyone else is having problems. I have 6 chicks, about 5 weeks old, and they've been in their outside coop for about 2 weeks. I started letting them go out of the coop about 5 days ago and 3 days ago I noticed an enlarged crop on one of the chicks. I did some research, checked her again in the morning, and it was, indeed, sour crop. I have not separated her from the flock. I did look up how to make her vomit, and tried it a couple times without a result. I don't think I was tipping her upside down enough. So, I tried again and achieved vomit. I've been making her vomit 2 different times a day, usually mid morning and late afternoon, as to give plenty of rest in-between so I don't stress her too much. She's hanging in there. Still has energy, running around and doing usual chicken stuff. I'm just hoping that I can get the problem out so she can get better. She is thin, but food coming up is digesting.