Sous Vide: Chicken Stock--2020
About
As easy as chicken stock is to make by conventional means on the stove, the application of sous vide offers distinct advantages.
Ingredients
Chicken bones--typically the back bone after removing the breasts and legs. Approximately 1 lb/450 g.
Carrots, 1 large, or 2 small.
Celery, 4 stalks.
Onion, 1 each.
Water, 1.5 quart/1.5 L.
Bouquet garni, as per your preference.
Equipment requirements
Immersion circulator, portable or stationary.
Heat rated container, minimum of 2 gallons/8 liters.
Heat rated sous vide bags or Ziploc gallon freezer bags.
Measuring cup.
Moist cheesecloth or paper towel.
Large colander.
Infrared or probe thermometer.
Instructions
Yield: 1 quart/1 Liter Level of difficulty--1.25
If you are accustomed to using channel vacuum, you might consider using an alternate method to make your stock. While it is possible to seal a bag with liquid in it, it is rather cumbersome. Be careful not to withdraw water from the bag and into the machine itself. I recommend a non-vacuum method.Procedure:
Preheat your sous vide bath to 183 F/84 C.
Load the chicken bones and vegetables in to a Ziploc gallon freezer bag. Set the bag on top of the preheated bath and slowly add a measured amount of water into the bag. The bag will slowly sink into the rack. Drape the unsealed bag's opening over the edge of your container and secure it with the container lid. 
Because of the characteristics of sous vide, the stock will not require reducing after straining. This is why you measure the water. One pound/450 g of chicken bones will make 1.5 quarts of stock. Process the stock for a minimum of three hours to fully render the bones and denature the vegetables. 
Place a colander over a pot or suitably sized container. 
Put the bag in the colander. 
Use a pointed knife to poke a hole in the bottom of the bag. Let the stock drain out. Discard the bag with the bones and vegetables still in it--this minimizes cleanup! 
The stock will be clear because the stock never actually boiled. If desired, line the colander with wet paper towels and pour the stock through it again--this will remove any albumins left in the stock. Cool the stock until it achieves 70 F/21 C and then refrigerate it. It's that simple. This stock can be used in place of water in any Lipavi recipe.