Dlmillion
Chirping
The fermentation process should produce a sour kind of stench similar to bread dough after it has risen. It definitely should have a strong smell. There is, however, always a slight risk of the feed becoming infected by less-desired bacteria's and/or molds. If it has become infected by such, you'll be able to clearly see whispy/moldy looking spots all over. If they are white, the feed is still most likely safe to feed to chickens but if they are colored or dark, then it would be best to trash it.
If you don't see any mold or bacteria colonies, then the smell is simply an indicator that the fermentation is going well!
