Sous Vide: Marrow Studded Smoked Meat Loaf, the Supermodel
About
While traditional meat loaf is made even more enjoyable as a result of sous vide processing, this dish can be further upgraded to achieve a complex and vibrant flavor and texture profile.
Ingredients
Ground Beef, 80/20, 3 lbs./1.4 Kg.
Beef marrow, 7 oz./225 g.
Celery, 2 stalks
Bacon, cut into strips, 3 oz./90 g.
Garlic cloves, smashed and peeled, 2 oz./60 g.
Egg, one ea.
White bread, 4 oz/120 g.
Milk, 1 cup/225 ml.
Salt, Kosher, 1.5 oz.
Ground Black Pepper,0.5 oz.
Equipment requirements
Immersion circulator, portable or stationary.
Heat rated container, minimum of 2 gallons/8 liters.
Heat rated sous vide bags.
Flat bottomed skillet, approximately 12″/30 cm. and 3″/90 mm deep.
Kitchenaid type mixer with paddle.
Loaf pan.
Kitchen tongs, metal.
Infrared or probe thermometer.
Instructions
Method
Remove the marrow from the bone using the point of a knife. Sous vide process the celery at 183F/84C for 1 hour Shock the celery in iced water until it achieves 70F/21C and refrigerate to 40F/4C. Use the knife to remove the tough outer fibers from the celery, just as if you were peeling a banana. Cut into uniform strips, so that it can be visible in the finished product. Fry the bacon on low heat until it softens; add the garlic. Continue to fry on low heat until the garlic is cooked through and soft but do not brown. 
Put the egg, the milk, and the bread in a Kitchenaid type mixer bowl. Use the paddle attachment to break up the bread. Add the beef, salt, pepper and mix. Add the marrow, celery, bacon, and garlic. Mix well. Stage the mixture, all in one piece into a loaf pan. Push it down to fit. This prevents the accumulation of air pockets. A chamber vacuum will effectively remove all the air from the meat loaf. This is one of the several unique and useful features of chamber vacuums but is not essential to success. You can now pack the meatloaf, pan and all, in an appropriately sized bag. A Ziploc Gallon Freezer bag is usually big enough for a 3lb./1.4Kg loaf. Process at 130F/55Cx6 hours to pasteurize. 
Remove the water from the vessel and refill with cold tap water and ice. When the loaf reaches 70F.21C, remove it from the bath and refrigerate to 40F/4C. Remove the meat loaf from the bag and place on a Lipavi rack and then on a sheet pan. Save the juices for clarification and use in other recipes and soups. Drizzle the meat loaf with this sauce , or your favorite brand of ketchup/steak sauce. Hot smoke the meat loaf at 225F/107Cx4 hours, It should achieve 140F/60C internally. The meat loaf can now be served or returned to a Ziploc Gallon Freezer bag, shocked again to 70F/21C and then refrigerated @40F/4C. I find the smoke flavor to be more prominent after cooling once the smoke has cleared from the air. Lipavi racks can be utilized during every phase of the sous vide processing, shocking, refrigerating and smoking stages of preparation! 
This meat loaf retains an appealing rosy color as a result of the low temperature processing and exposure to gases inherent in the smoking process. The texture is uniquely unctuous, but firm enough to stand up to thin slicing. Click HERE for the link to an exciting application of this item!