Rhineland top-fermented beers
Kölsch and Alt: the difference
Kölsch and Alt differ in color, bitterness, and legal status: Kölsch is pale, delicate, and protected as a designation of origin, while Alt is copper-brown, more assertive, and unprotected. Both are top-fermented and cold-conditioned. A good 40 kilometers of the Rhine separate two distinct beer worlds.
What Kölsch and Alt have in common
Along the Lower Rhine, brewers held on to top-fermenting yeast longer than in Bavaria, where bottom-fermentation took hold early on. Kölsch and Alt are the heirs to this tradition. The name Altbier points directly to this, referring to the "old," top-fermented way of brewing.
Both are fermented with top-fermenting yeast at moderate temperatures and then cold-conditioned for weeks afterward, much like a lager. Experts call these hybrid beers. The cold conditioning smooths out the fruity esters, meaning the aroma compounds produced by top-fermenting yeast. The result is beers that feel finer and cleaner than an English ale, yet show a touch more fruit than a Pils.
What is a Kölsch? Convention and protected origin
In the glass, Kölsch appears pale and clear, 7 to 10 EBC. According to BJCP, it has 11 to 12.4 percent original gravity, 4.4 to 5.2 percent ABV, and 18 to 30 IBU. In flavor, delicate malt sits alongside refined hops, often with a hint of pear or apple from the yeast. The finish is dry. It's served in the Stange, a narrow, cylindrical glass that the Köbes, the waiter in the brewhouse, brings to the table on a tray.
Two levels govern what may be called Kölsch. On March 6, 1986, 24 breweries signed the Kölsch Convention, a private agreement within the Cologne Brewers' Association. It stipulates: top-fermented, pale, clear (meaning filtered to brilliance), highly attenuated, hop-forward, a full-strength beer, brewed according to the Reinheitsgebot, and served in the Stange. Highly attenuated means the yeast has processed nearly all the sugar. EU protection as a Protected Geographical Indication has only existed since November 25, 1997. Kölsch may be brewed in Cologne and by a few breweries in the surrounding area that were already brewing it before the Convention.
The brewhouse has its own rules. The narrow Stange is small so the beer stays fresh and cool. When a glass is empty, the Köbes usually sets down a full one without being asked. If you've had enough, you place a beer mat on top of your glass. This makes Kölsch a beer of small, fresh sips, not one for nursing the same glass through a long evening.
What is an Altbier? Düsseldorf's copper-brown beer
Altbier brings copper to mahogany tones to the glass, 18 to 33 EBC. It's brewed with darker malts such as Munich malt and considerably more hops. BJCP lists 25 to 50 IBU, meaning more than double that of a Helles at the upper end. This comes alongside 11 to 12.9 percent original gravity and 4.3 to 5.5 percent ABV. The flavor combines bread crust and nut with a firm, dry bitterness.
The home breweries of Düsseldorf's old town still shape the style today, including Zum Uerige, Zum Füchschen, and Schumacher. It's served in a small, straight tumbler glass. Unlike Kölsch, Düsseldorfer Alt has no EU protected designation of origin and no comparable convention. So any brewery can brew Altbier, and plenty do throughout the Lower Rhine region. On certain occasions, some home breweries also tap a stronger, more heavily hopped Alt called Sticke in Düsseldorf, which is only available for a short time.
Kölsch or Alt? Here's how to tell the difference
The quickest test is color. Pale straw-yellow means Kölsch, copper-brown means Alt. The second test comes on the tongue: Kölsch is delicate and almost wine-like, while Alt is bolder, maltier, and more bitter. Anyone who places a Kölsch next to a Helles will also notice that the top-fermenting yeast leaves a subtle fruity note that the bottom-fermented Helles lacks.
The rivalry between the two cities is legendary. In the taverns of one city, you generally won't find the beer of the other. Technically, though, the two styles are close relatives: same yeast family, same cold conditioning, but different malts and hop additions. If you're tasting both back to back, start with the Kölsch. Otherwise, its delicacy gets lost next to the bitterness of the Alt. They pair differently with food too: Kölsch suits light dishes and salads, while Alt complements roasts, mustard, and hearty Rhineland fare.