The true Kolsch designation refers to a beer style that can only be brewed within a 20 mile radius of metropolitan Koln, in accordance with the Kolsch Convention. This document, signed in 1985, protects the definition of Kolsch designating where it can be produced, as well as specifying the shape of the glass in which it is to be served. There are producers throughout the world, however, who loosely refer to their brews as Kolsch, Kolsch-style ale, or Summer Ale.
Guidelines set forth in 2004 for the Beer Judge Certification Program categorize Kolsch as a light hybrid beer, a specialty brewing style that merged the British method of hot fermenting beer (to develop more flavor) with the German manner of cold lagering (for greater smoothness). The result is a balance between full alcoholic strength, subtle fruit aroma, subdued maltiness and distinct noble hops bitterness.
Kolsch can range in color from pale straw to light 18 K gold, with brilliant clarity due to attentive filtering. It has a delicate white head that may not persist, and may leave specks of lacing on the glass. The glass, of course, should be simple: a tall, straight cylindrical 200 ml glass.
The aromas are intoxicating – a nose of subtle fruit from fermentation (apple, cherry, citrus, or pear), low malts, a touch of noble hops, with possible winey character. This sets the stage for the soft, rounded flavors. An almost imperceptible fruit sweetness gives way to the medium bitterness and delicate dryness. You may detect flavors of biscuit and nuts, wheat or light hay. Light to medium in body, Kolsch is very smooth, with medium carbonation. The finish leaves a clean, refreshing tang and warming in the throat.
You may elect to travel to Koln for authentic Kolschbier. Brewers Publications Book by Eric Warner has an excellent appendix covering all the major breweries in Koln, along with their respective pubs. Of course, there are hundreds of Kolsch-style ales available throughout North America, with dozens of brews worthy of high accolades.
Here is a genuine Kolsch beer recipe:
9.4 lbs 2-row pale malt
1.65 lbs wheat malt
25 g Hallertau @ 4% AA (FWH)
15 g Hallertau @ 4% AA (45 min)
15 g Hallertau @ 4% AA (30 min)
12 g Saaz @ 3.4% AA (10 min)
Wyeast 2656 Kolsch
Makes 23 litres.
Mash 75 min @ 64°C (147°F)
Mash out 10 min @ 77°C (171°F)
Sparge 45 min @ 70°C (158°F)