Local farmers would process the milk from their own cows by removing the butterfat or cream, which was hauled in cream cans to the cheese factory, while the skim milk or whey was fed to hogs raised on the same farm.
The Paris newspaper Le Monde reports that the sauce as served by Le Relais de Venise – L'Entrecôte is made from chicken livers, fresh thyme and thyme flowers, full cream (19 percent butterfat), white Dijon mustard, butter, water, salt, and pepper.
In 1911, the American Dairy Science Association's Committee on Official Methods of Testing Milk and Cream for Butterfat met in Washington DC with the U.S. Bureau of Dairying, the U.S. Bureau of Standards and manufacturers of glassware.