Peanut Butter Fudge

Boiling sugar and milk to the soft-ball stage (234-240°F) creates a supersaturated solution that crystallizes when beaten, forming fudge's characteristic smooth texture. The five-minute boil time evaporates enough water to reach this critical temperature. Beating the hot mixture introduces air and agitation that promotes the formation of tiny sugar crystals rather than large, grainy ones, while the fat in peanut butter interferes with crystal formation to create a creamy, melt-in-your-mouth consistency.