In all the recipes I see for making creme fraiche, the ingredient amounts--though all over the place--are something like 2 tablespoons of buttermilk to 1 cup of cream and many variations thereof. However, in 'Le Cordon Bleu Complete Cooking Techniques', they show 2 cups of buttermilk to 1 cup of cream.
I can't find any errata online so I'm wondering if there is a reason for that. Is this a French thing or possibly an uncaught typo (though the book is several years old)?