When you ferment grains, you get two different products depending on how long you ferment it. The first product will be lactic acid from our lovely probiotic organisms such as lactobacillus and bacillus subtilis etc. This makes some bubbles and a sour, yougurty smell. If you leave this too long, the lactic acid producing bacteria will essentially produce so much lactic acid that they raise the pH too high for them to live. It is at this point that you create the perfect conditions for alcohol producing yeast to start flourishing and producing alcohol.
The lactic acid stage is a nice fermented feed. The alcohol stage is a nice sourdough starter. I make my own sourdough starter from fresh, organic wheat, barley or rye. Grains grown out in the open will be naturally bathed in windborne wild yeast. I grind the grains in my Kitchenaid grain mill attachment and I put them in a container with some pineapple juice which actually has the perfect pH to hasten the killing off of lactobacillus and to promote the growth of yeast which will let my bread rise. If you have gluten issues or if you just want to stop paying so much for yeast that was made with who knows what kind of grains and processes, this is the way to go.
But I digress. My point is that you CAN make drunk chickens but only if you ferment for too long.