You might be interested in what Jim Wallace has to say @ Cheesesemaking.com go to the recipe section.
Here's the bit about washed rind, most other St. Paulin recipes I've got add b.linens to the milk, then brine wash with b.linens
"The 'Trappist' style cheese is one with a semi-soft body and is usually ripened with a washed or smeared rind resulting in a yellow to orange rind. Unfortunately, the commercial versions today are made with an orange dye sprayed onto the surface at the end of the ripening process.
The traditional ripening is due to a series of light brine washes which selects for a specific bacteria (coriniforms including B.linens) that naturally produces a rather colorful surface and is actually responsible for producing enzymes that cause the cheese to ripen to the center producing a very soft and aromatic cheese.
This cheese process is somewhat similar to the more "aromatic" cheeses, such as Limburger, but is much milder due to a more restrained ripening.
The most notable factors in making this cheese are:
the series of light salt brine washes,which are very important in setting the stage for the special enzyme production which slowly moves towards the center of the cheese.
the high moisture of the cheese body, which will allow these enzymes to move quickly.
a high humidity in the aging space to keep the cheese surface from drying out.
As the process of ripening progresses, the enzymes begin to break the proteins into smaller and smaller components, thus reducing the acidity and developing flavor in the cheese. As ripening continues, this moves deeper and deeper into the cheese until the entire interior of the cheese has been ripened."
http://www.cheesemaking.com/PortSalut.html