I have about 4 lbs of grass-fed beef marrow bones. I'm going to roast them, eat the marrow (refrigerate any left over), and throw them in my slow cooker to make broth. My understanding is that roasting the bones first makes the resulting broth much more flavorful and delicious.
I also ordered knuckle bone cartilage and oxtail from US Wellness Meats. Should I do any sort of roasting/prepping with these items, or just throw them in the pot (after they've thawed, of course)? My goal is a very gelatinous and delicious broth. This will be my first time making it.
Roasting is a culinary enhancement. It will provide flavor and color to the stock but won't really effect the nutritional profile. Since you are already roasting the marrow bones, throw the knuckle and tail in w/ them.
If you really want flavor and color use a "mirepoix" and thoroughly "deglaze" the roasting pan.
Mirepoix = onion, carrot, celery chopped and roasted w/ the bones. I also like to add garlic cloves, coarse-cracked (or whole) black pepper, and dried thyme to the roast.
Deglaze = remove the bones and drain the fat from the pan. (I would add the rendered fat into the crock pot) The browned remnants on the bottom of the pan (the "fond") need to be transferred to the stock. Simply place the roasting pan on the stovetop, add 1/4 inch of water (or red wine), bring to a simmer and scrape the fond free w/ a wooden spoon. Then pour everything into the crock pot.
Parsley stems are also very flavorful. Use a little vinegar (1 Tbsp: gal.)
(For extra gelatin, chicken feet are superb if you can get them. But they will change the quality of the fat cap.)
I oil the bones lightly and salt and pepper them, then roast them at 450ºF for 3 hours, then you make your broth, the deepest the "brownage" the better the flavor.
Here's a link to two recipes of mine, one for bone broth and one for Oxtail stew:
"roasting the bones first makes the resulting broth much more flavorful and delicious" -- Yes, but eating the marrow does not. I love marrow, but if I am making broth, I crack the bones open and let the marrow flavor the broth.
Oxtail is simply too good just to make broth with. Braise it, and then keep the bones for your broth. -- http://www.simplyrecipes.com/recipes/glazed_oxtails/
I just put oxtails in the crockpot. What comes out is delicious meat all tender and falling off the bone. The leftover juice turns into meat jello with a layer of fat to skim and save for other things. I chopped the meat jello into cubes and mixed it with fresh tomatoes for a tasty salad. I imagine if you put the oxtails in with your other bones, the broth would be thick and gelatinous and full of meat. Put the leftover oxtail bones in with your other bones, and that little bit of gelatinous stuff sticking to the ends of each bone will thicken the broth, too. Just maybe not as much as the complete oxtails with meat included.
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