Frozen custard mix has a high content of butterfat (min of 10%) and egg yolk (1.5%).  These specific ingredients are what give the custard a thick and creamy texture.  The mix is poured into the hopper on the top and is gravity fed into the machine. 

The custard comes out of the hole in the back.

The barrel is refrigerated so the custard freezes to the inside of the barrel.  The custard is scraped off the sides and pushed forward by a set of paddles and blades called an agitator.

The speed at which the product leaves the barrel minimizes the amount of air in the custard which gives it the smooth and dense consistency.  The product leaves the barrel where it falls into a frozen can.

From there, the custard is scooped and ready to enjoy.