Ingredients are simmered gently in a copper pot. A good thermal conductor, copper spreads heat evenly and prevents "hot spots" that might scorch the candy.
The Fudge House at Fishermans Wharf in San Francisco, California, makes its signature product in relatively small batches. The cooking processfreely observable in the small shopis not all that different from fudgemaking at home.
At least once during the cooking process, the cook brushes water down the inside walls of the cooking pot to dissolve any crystals that have formed which might cause the candy to crystallize prematurely.