FWIW, I ran into the same problem yesterday with my beef stew, at the same stage. Relating this because I make my beef stew the Japanese way, which is probably similar to how Alter made his. Had browned large cubes of chuck in flour, looked really nice and seared, rested those and then put on some diced carrots and onion in a good 3-4 tablespoons of butter, deglazed with Japanese canned fond de veau and a splash of brandy, added red wine, added canned consomme, re-added beef. Threw in a bouquet garni I rigged up from some negi and herbs, threw a half of a fresh tomato I found in the fridge, some bay leaves, brought up to heat and then simmered - turned out grey. My problem was probably that I dredged the chuck too heavily, and sauteed my onions in too much butter - needed far less fat at that point. The simmer just let the flour crust on my beef dissolve and emulsify with the butter-logged onions and carrots, and a couple hours later I just had gravy, essentially. I let it cool down, picked all the beef out, strained the onions and carrots out (they were spent at that point anyway) until the stock was running smooth, put in fridge, took it out and skimmed the remaining fat off, added some water, repeated the skimming until I got my fat out almost completely, including some rendered beef fat that came off the meat. Pretty much as good as new now. I have had it in the fridge chilling overnight, waiting for one more fat skimming, and then I'm gonna reheat it, drop a couple halved onions in there to reduce the liquid a bit, and then add some canned Japanese demiglace to finish it off. It should be pretty good now.