Any type of raw or pasteurized dairy cream can be used for this recipe, although it is best to avoid ultra-pasteurized dairy cream due to its unpredictable results (some folks have luck with it and some do not). Different creams and their processes may produce different results.
Heavy/whipping cream, light cream, and half & half, will all produce slightly different results. Raw cream may be used, however, raw cream may yield a thinner version of Crème Fraîche since certain proteins have not been activatedby heating.
Our experience here has shown that heavy (whipping) cream works best when simply pasteurized at the defined temperature.