Beurre d'Isigny Cultured & Churned Spring ButterButter at Its Most Alive. Made with Early Spring Milk. This is Isigny Sainte Mre at its most seasonal and special. Made with grass fed milk produced during early spring when Norman cows first return to pasture after winter and the grass is at its most vibrant and nutrient rich this cultured and churned butter captures a fleeting moment of exceptional quality. Bacterial cultures are added before churning, developing a complex, tangy depth that sets