Premier chocolatier Alice Medrich, who knows fudge inside and out, likes it dense with dark chocolate, firm enough to cut neatly, and melt-in-your-mouth velvety smooth. Such fudge makes a perfect Valentine's Day gift.
Medrich's recipe for fudge is a keeper, but the tips below ensure the best results for any recipe. Sweet science is the answer.
Food technologist George K. York explains the critical points of fudge making:
A. TO AVOID GRAININESS. The sugar (sucrose) in fudge is responsible for its texture. As sugar cooks, it physically changes, forming crystals, some tiny, some big. Graininess results when sugar crystals get large. To thwart the formation of large sugar crystals, York has three suggestions: Wash down the pan sides with water as the fudge cooks. Monitor the temperature carefully with an accurate thermometer to make sure the mixture does not overcook. And use corn syrup (glucose), which is not prone to crystallization.
B. FOR FUDGE THAT CUTS WELL. Agitating, or stirring, the fudge mixture after it is cooked affects the size of the sugar crystals, which controls the consistency of the finished fudge. If you stir when the mixture is too hot or too cold, it will either stay soft or get too firm to cut neatly. It is important to let the fudge mixture cool to 115° before the last stirring step.