To make this creme fraiche we used a technique from our book Ideas in Food: Great Recipes and Why They Work. It is one of many ideas which is woven within the text of the essays rather than presented as a step by step recipe. We blend buttermilk and creme fraiche together to culture the cream. The twist in this version is the addition of whole coffee beans. The cold or room temperature infusion of the beans into the cream is one we have used over the years to make white coffee ice cream. The result is a tangy rich cream, thick and spreadable with the aromatic notes of roasted coffee. In its current form it is great on toast, enriching risotto or as a liason in sweet pea soup. Tomorrow it may end up as ice cream or perhaps churned into our coffee butter. What we have learned in our technique extrapolation is that we have another form with which to add flavor to food.