Preheat oven to 325°. Combine the 10 egg yolks with the sugar, vanilla and salt in a medium sized mixing bowl. In a saucepan heat the quart of half & half over medium hi heat. DO NOT bring to a simmer. Heat it till it just starts to steam and coats a metal spoon. Turn off the heat.
Temper the egg mixture. Slowly pour about a ½ cup of the hot liquid into the eggs, as you quickly whisk. This heats the eggs slowly so they do not cook and curdle. We don't want scrambled eggs in our custard.
After the eggs are tempered slowly pour the egg mixture into the saucepan with the half & half as you quickly whisk the liquid.
Measure the hot liquid into ramekins or small baking dishes to a ¼ inch from the top. Place the filled ramekins in a large casserole baking dish.
Bake in a water bath by pouring hot water into the casserole dish to fill the empty space around the ramekins.
Bake in preheated oven for 50 minutes. Test for doneness by carefully moving the dish side to side. The tops of the custard should move a tiny bit like Jello. NOT move like liquid. If it moves to much cook for another 5 minutes. Test and keep cooking in 5-minute increments till done.
Immediately remove custards from the water bath by lifting out with a metal server, and place on a cooling rack. Place the cooling rack into a cooking sheet, and chill in the refrigerator for 4 hours to overnight.
Right before serving set all the custards out on the counter, and one at a time evenly spread 1-2 teaspoons of white sugar. Then use a butane cooking torch to move around the outer edge in a circular motion, moving into the center, and back out to the edge till the sugar is all camelized. Make sure the gas flow on the torch is set in the middle. You don't want the flame too high or too low.
***If you do not have a torch that's OK! In a 6-inch frying pan spread out an even layer of white sugar. DO NOT STIR! Let it sit on medium high heat till all the sugar melts and turns dark brown. Immediately drizzle a little bit on top of one custard at a time. As you drizzle, slowly tip and turn the custard to move the caramel slowly around to coat the top in a thin crust. You may need to melt and carmelize more sugar a few times to get all the custards topped.