I'm not Bee but thought I'd chime in. Sour crop is an overly acidic crop. Fermented feed is mildly to moderately acidic. It could be your EE is avoiding sour foods. Or in the case of your recent observation of her picking out seeds from the FF, she needed a tiny bit of sour or even just really desired those seeds.Bee, you suggested I report back with developments with my EE with sour crop. She has survived it and is slowly getting better, but she still won't eat the FF. How she's survived is a mystery, though she must be getting something when she free-ranges, along with squash and carrots and raisins that I occasionally provide the flock. This morning, for the first time, I saw her at the FF trough. On closer observation, though, I saw she was just picking out the seeds, and she really didn't stay too long at it. The past couple days I've had a broody in a wire cage, and I provided some dry chick starter since she wouldn't touch the FF. My EE has been eating that when I let the broody out to stretch. I wonder if this is a natural, self healing strategy. Maybe there's something about the FF that this recovering EE can't handle. Any ideas? And why wouldn't a broody want the FF, either?
That's Kahm yeast. Do a google image search. Kahm yeast is harmless. It's not essential to the SCOBY but it won't hurt. I don't get it on fermented feed, but sometimes I do on fermented pickles in which case I do remove as much as I can. It can add a mild fruity flavor, again, it's harmless. But I don't care for fruity pickles!I started my chicks on fermented feed about two weeks ago ( when they were only about a week old). The first time I made it I used medicated chick starter, water and whey from making yogurt. I ended up throwing it away after a week because I thought it got moldy. It had spider web like white strands all over the top of it. I looked on line and read NOT to use whey from yogurt and figured that was the problem and threw it out. The new batch has no whey, just water, and "molded" in only two days. I'm not sure if it is actually mold. I've been skimming it off the top and still feeding it to them, it doesn't smell bad and they still seem to like it. I tried looking up pictures but it didn't really help. I'll try and post pictures of it. I keep it covered with a glass lid, seen next to Rosie, who decided she would help herself to some breakfast!