This is a 3 part recipe:
1. Make stock:
Chicken~ 6-8 hours
Turkey~ cooked carcass/cooked wings 3-31/2 hours
Beef~ 6-8 hours
Pork~ 12-24 hours
Vegetable~ 45 mins.
Once the stock is done, pour the stock into a colander with a big pot underneath. Discard the bones and mirepoix, and place the stock back onto the stove.
2. Reduce the stock
On low heat, the stock will reduce to a syrupy consistency. That is what you are going for, if it is still loose like water, keep reducing. You will have to keep watching the pot every hour since you don't want to lose all your liquid and it starts to burn. When the stock gets reduced to an inch of liquid, it is done.
3. Place a silicone mat, silpat, or parchment paper down on a cookie sheet, add your reduced thick stock and spread a thin layer, place it back in the oven on 140 degrees till it looks like glass. Here you can take this as your bouillon cubes, you would wrap it and place in the freezer. If you decide you don't want to make this into a powder.
4. Break up the glassy stock into shards, and take the large pieces into a spice grinder or a small grinder, since a large one can't get every piece. You want a fine powder, and you have to go through a couple of times since it is a process to break down.
5. On a silicone mat or aluminum foil, take the powder and spread it out and place it the oven at the lowest degree your oven can do, and let it dry out for 20 minutes. Let it cool and place it in the freezer.
Chef's Note: Please store these in the freezer since this recipe doesn't have any preservatives nor msg. I do not recommend fish, since over cooking it will turn bitter and will be more concentrated.