A month and a few days into primary fermentation... i.e., earlier today... everything seemed to have stalled. The wort still looks like chicken gravy, and despite an obvious yeast presence there was no visible yeast activity and no change for about a week. A small sample was tasted; flavors indicated hop bitterness, yeasty sourness (not an infection as far as I can tell, thankfully, just yeast flavor) and a profound bready, starchy character.
"That tears it," I think to myself, and into this month-old primary fermentation with a three-inch layer of trub in a gallon jug I throw 1/8th of a teaspoon of alpha amylase. A few hours later it's bubbling away again, and we will see what we will see.