Question: Tripel beer was first introduced in 1956, by which Belgian abbey brewery?

Context paragraphs:
Tripel Karmeliet: Tripel Karmeliet (Dutch for "Tripel Carmelite") is a golden Belgian beer with high alcohol by volume (8.4%), brewed by Brouwerij Bosteels in Buggenhout, Belgium.  It was first brewed in 1996 and uses three cereals: wheat, oats and barley.

Westmalle Brewery: Westmalle Brewery (Brouwerij der Trappisten van Westmalle) is a Trappist brewery in the Westmalle Abbey, Belgium.  It produces three beers, designated as Trappist beer by the International Trappist Association.  Westmalle Tripel is credited with being the first golden strong pale ale to use the term Tripel.

Smithwick's Experience Kilkenny: Smithwick's Experience Kilkenny (formerly St. Francis Abbey Brewery and Kilkenny Brewery) is a brewery-turned-brewery-tour located on the Medieval Mile in Kilkenny, Ireland.

Weyerbacher Brewing Company: Weyerbacher Brewing Company is a brewery in Easton, Pennsylvania, United States, founded in 1995 by Dan and Sue Weirback.  The brewery is well known for its "huge taste" beers.  Most of their brews are high in alcohol, with QUAD clocking in at 11.8% alcohol by volume, and a one-off 10th anniversary ale called Decadence brewed to 13% alcohol by volume.  Hops Infusion is one of the bitterest examples of the IPA style.  Weyerbacher is also a pioneer of aging beer in wooden barrels previously used for aging bourbon.  This process was used to transform Old Heathen imperial stout into Heresy, Blithering Idiot barley wine into Insanity, Merry Monks Belgian tripel into Prophecy, and QUAD Belgian quadrupel into Blasphemy.  These four styles are all very high-alcohol brews with complex flavor profiles; the barrel-aging lends additional oak and whiskey flavors.  The results have been widely praised by fans of huge beers, though persons accustomed to more mainstream beer may find them an acquired taste.

Pizza Port: Pizza Port Brewing Company is a brewpub with five locations in Southern California: Solana Beach, two in Carlsbad (Downtown and Bressi Ranch), Ocean Beach and San Clemente.  A former Pizza Port location in San Marcos spun out of Pizza Port in 2006 and is now an independent operation, the Port Brewing Company / Lost Abbey brewery.  It has received multiple awards, including "Small Brewpub of the Year" for both 2003 and 2004 by the Great American Beer Festival and six awards for its beers at the World Beer Cup.

Herkenrode Tripel: Herkenrode Tripel is a Belgian Abbey beer brewed for the Herkenrode Foundation by commercial brewery St. Joseph in Opitter (Bree, Flanders in Belgium).  It is on the market since July 2009.  It has an alcohol by volume percentage of 7%.  In June 2009 the Federation of Belgian Brewers awarded the beer the name and the logo of Recognized Belgian Abbey Beer.  In the Herkenrode Abbey in Hasselt, which was founded in 1182, beer was brewed until the French Revolution in the brewery of the abbey.

Tripel: Tripel is a term used by brewers or people mainly in the Low Countries, some other European countries, and the U.S. to describe a strong pale ale, loosely in the style of "Westmalle Tripel".  The origin of the term is unknown, though the main theory is that it indicates strength in some way.  It was used in 1956 by the Trappist brewery, Westmalle, to rename the strongest beer in their range, though both the term Tripel and the style of beer associated with the name (strong pale ale), were in existence before 1956.  The style of Westmalle's "Tripel" and the name was widely copied by the breweries of Belgium, and in 1987 another Trappist brewery, the Koningshoeven in the Netherlands, expanded their range with a beer called "La Trappe Tripel", though they also produced a stronger beer they termed "La Trappe Quadrupel".  The term spread to the U.S. and other countries, and is applied by a range of secular brewers to a strong pale ale in the style of "Westmalle Tripel".

Corsendonk: Corsendonk is a Belgian beer brand.  The brandname refers to the Priory of Corsendonk in Oud-Turnhout; which was in operation from 1398 to 1784, and was rebuilt in 1968 as a hotel complex by new owners Corsendonk Hotels.  In 1982, on the 125th anniversary of the Oud-Turnhout municipality, Jef Keersmaekers, grandson of Antonius Keersmaekers who had founded a brewery in 1906, was approached by the local tourist office to use the Corsendonk name for its abbey association, as an abbey beer marketing technique.  He launched "Pater Noster", now called "Corsendonk Pater" (or ""Abbey Brown Ale"" when marketed in America), and "Agnus Dei", now called "Corsendonk Agnus" (or ""Abbey Pale Ale"" when marketed in America).  As the family brewery had closed down in 1953, the beers were contracted out to other breweries, including Brasserie Du Bocq, who now brew all the brands.  Other brands include "Corsendonk Blond", "Corsendonk Bruin" and "Corsendonk Christmas Ale".

Klosterbrauerei Andechs: The Klosterbrauerei Andechs is a monastic brewery in Andechs, Upper Bavaria, Germany, well known for its Andechser beers.  The brewery is run by the monks of Andechs Abbey, a priory of St. Boniface's Abbey, a Benedictine abbey situated 40 km away in Munich.  It is the only monastic brewery in Germany that brews Bock beer year-round for nationwide distribution.  Every year, the brewery produces over 100000 hL of beer.  A portion of the beer is served on-site at the abbey; the remainder is exported throughout Germany and worldwide.

St. Feuillien Brewery: The St. Feuillien Brewery is a Belgian brewery in Le Roeulx, Belgium, which was founded in 1873.  The brewery, which makes abbey-style beer, has been operated by the Friart family all this time, except for an 11-year hiatus that ended in 1998.  Beers brewed by St. Feuillien include a brown ale and a tripel, the latter of which praised as one of the best tripels available.  A recent addition to their selection is a saison, "which has grown steadily to be up with the best".  In 2016, the brewery launched an IPA called "Belgian Coast".

Supporting paragraphs: Tripel Westmalle Brewery
Answer: Westmalle Brewery