Trappist is made by one of 6 breweries in Belgium or 1 in the Netherlands. No one else makes a Trappist Ale that can be termed as such. This style of beer must be made in one of 7 Trappist monasteries to be called a Trappist. The six Trappist producers are Chimay, Rochefort, Orval, Westmalle, Westvleteren (good luck getting a hold of one of these), La Trappe (also called Koningshoeven) and Achelse Kruis. All of these are made by monks in the monastery. So, unless your Trappist is one of these, then it’s not a Trappist. There doesn’t seem to be a set way or style to which a Trappist must conform, being that the important part is where and by whom it is made.
Just by way of clarification, Westvleteren only takes orders by phone and only reluctantly. They are also the only one among the 7 that only employs monks who are a part of the Abbey. I was reading a book by Sam Calagione and Tim Hampson, in which they talk about this monastery and its attitude. Here are two points that they emphasize. First, the monks brew to pray (i.e., they do it as a means of support), not pray in order to sell. Here is a quote from Joris (who is responsible for the brewing): “We refuse to go into an endless spiral of producing more, then having to sell more, and bring more brothers into the process, or even having to hire outside staff.” I take it he’s not a venture capitalist. Unless you’re in Belgium and specifically call this place, it’s pretty unlikely that your going to get a hold of this.
Trappists often come in Doubles or Triples, and there are many varieties in between. Most are moderately strong to very strong in alcohol content, usually 6-10% ABV. They also tend to be fruity and lightly hopped. In addition, they often use candy sugars to give a more malty impression to their beer. They are also top-fermented, which makes them Ales. There is a German counterpart to a Trappist called a Kloisterbier.
Abbey Ales are beers which are often styled after Trappist Ales but cannot be called Trappist because they weren’t produced in a monastery. Abbey Ales are called such because they usually attach the name of a former monastery to their beers. Once again, there are not really any strict guidelines as to what constitutes an Abbey Ale. They tend to 6-8% ABV and have many of the same qualities mentioned above (fruity, etc.). These beers are often full-flavored and wine-like in quality.
Double (Dubbel) and Tripel Ales:
A Dubbel or Tripel Ale usually a subcategory of an Abbey Ale or a Trappist Ale. The original reason behind calling a dubbel by it’s name had to do with the notion that it had twice the gravity of common beer. This would make it more flavorful and stronger in alcohol. It would follow that one would assume that a tripel is three times the gravity of a common beer. This is not necessarily the case, but it can be approximately true. Both of these types can be pretty strong, often 7-11%, the stronger being a Tripel.
I would encourage anyone to try both types of these beers; they are delicious. This is especially true of Trappist Ales.