Bland Demi Glace'
I've been making demi-glace out beef bones for years. I get about 15 lbs bones from my local butcher. Roast them at 400 until they begin to brown (usually 60-90min). onion/celery/carrots/tomato paste until well browned. I mix it all together in a 4-gallon stew pot with cold water, add a bouquet garni of parsley, thyme, and bay leaf, and simmer all day. I drain all solids and the demi is chilled in the fridge overnight, and fat is removed. I then reduce it by half and chill again. It has the consistency of very firm gelatin, and color of coffee. I cut it into cubes and freeze.
Ok, this year the consistency was perfect, it has a great mouth-feel, but the flavor is not incredible. It seems hit-or-miss from year to year whether I get a deep rich umami flavor or a bland rich beef gravy flavor. Any ideas?