Often confused with Port Salut cheese, which it is the same as — but not quite.
In 1959, the monks at Notre Dame du Port-du-Salut Abbey at Entrammes (between Laval and Angers), on the Mayenne river in the département of Mayenne in Brittany, France, sold the name, recipe and rights for Port Salut cheese to “Société Anonyme des Fermiers Réunis” (SAFR), part of the BEL group. To meet market demand, SAFR of course changed production methods a bit. The biggest change, perhaps, was that the rind of the cheese had been washed with brine during aging; this no longer happens because it is wrapped in plastic right away.
After the sale, the monks continued making the cheese their old way, including washing the rind. They couldn’t call it Port Salut any longer, as they had sold that name, so they called it “Entrammes.” But as demand for that cheese grew, the monks couldn’t keep up and so ceased commercial production.
Entrammes Cheese is now often used to mean a family of cheeses, which are also called Port du Salut style cheese or Saint Paulin cheese.
Some unrelated Entrammes history: the Treaty of Entrammes was signed there in 863. Charles II of France (840-877), aka Charles the Bald or Charles le Chauve, ceded to Brittany the “pays entre deux eaux” — the land between two waters, the Sarthe et Mayenne, which was a part of Anjou and Maine. In return, King Solomon of Brittany swore allegiance to Charles II, and agreed to pay tribute.