The Brewer

Lager Beer

Lager Beer: The Cold-Conditioned Classic

Lager is a type of beer that is conditioned at low temperatures. It may be pale, golden, amber, or dark. While the word “lager” often brings to mind the ubiquitous pale lagers found worldwide, the category encompasses a vast range of styles, from the dark, malty Dunkel to the crisp, bitter Pilsner.

The name comes from the German word lagern (to store), referring to the tradition of maturing the beer in cold caves for weeks or months.

The Defining Characteristic: Bottom Fermentation & Cold Storage

The primary difference between lagers and ales lies in the yeast and the temperature at which they ferment.

The Yeast

Lagers use Saccharomyces pastorianus, a hybrid yeast strain (a cross between Saccharomyces cerevisiae and the cold-tolerant Saccharomyces eubayanus). Unlike ale yeast which rises to the top, lager yeast tends to settle at the bottom of the fermentation vessel.

The Temperature

While ales ferment quickly at warm temperatures (15–24°C), lagers ferment slowly at cool temperatures (7–13°C). This slower metabolism means fewer esters (fruity flavors) and phenols (spicy flavors) are produced.

The Lagering Phase

After the primary fermentation is complete, the beer undergoes a period of “lagering” at near-freezing temperatures (0–4°C) for several weeks or even months.

  • Clarification: The cold causes proteins and yeast to drop out of suspension, resulting in the brilliant clarity lagers are known for.
  • Flavor Cleanup: The yeast continues to work slowly, reabsorbing compounds like diacetyl (buttered popcorn) and sulfur (rotten eggs), leaving a beer that is exceptionally “clean” and crisp.

A Brief History

Lager brewing evolved in the 15th and 16th centuries in the Bavarian region of Germany. Local laws (the Reinheitsgebot) required brewing to take place during the cooler months to prevent spoilage. Brewers discovered that by storing their beer in icy mountain caves over the summer, the beer became smoother and clearer.

The 19th century saw two major breakthroughs that changed lager forever:

  1. Refrigeration: Carl von Linde invented commercial refrigeration in the 1870s, allowing lagers to be brewed year-round and exported globally.
  2. Pilsner: In 1842, in the city of Pilsen (Bohemia), the brewer Josef Groll created the first golden lager. Using pale malt, soft water, and Saaz hops, he sparked a global revolution that shifted preference away from dark, heavy beers.

The Lost Art: Decoction Mashing

Historically, many German and Czech lagers were brewed using a technique called Decoction Mashing.

  • The Process: Brewers would remove a portion of the mash (grain and water), boil it in a separate kettle, and then return it to the main mash to raise the temperature. This might be done once, twice, or even three times.
  • Why?: Before thermometers, this was a reliable way to hit temperature targets. The boiling also helped break down the unmodified malts of the time.
  • The Flavor Impact: Boiling the grain creates Maillard reactions (browning), adding rich notes of bread crust, toast, and caramel that are difficult to replicate with infusion mashing. While many modern breweries skip this time-consuming step, traditionalists argue it is essential for an authentic Czech Pilsner or Oktoberfest.

The lager family is surprisingly diverse.

1. Pilsner

The most influential beer style in history. It is characterized by its brilliant golden color, high clarity, and a pronounced floral hop bitterness (usually from Saaz hops).

  • German Pils: Crisper, lighter body, higher bitterness.
  • Czech Premium Pale Lager (Bohemian Pilsner): Richer malt body, slightly darker gold, softer bitterness.

2. Helles

A Munich specialty created to compete with the Pilsner. It is maltier and less bitter, emphasizing the sweet, grainy flavor of German Pilsner malt. It is “liquid bread.”

3. Märzen (Oktoberfest)

An amber lager with a rich, toasty malt profile. Traditionally brewed in March (März) and stored in caves until the autumn festivals.

4. Dunkel

The original Bavarian lager. It is dark brown and features deep flavors of bread crust, caramel, and chocolate, without being heavy or overly sweet like a stout.

5. Bock

A strong, malty lager historically brewed by monks for sustenance during fasting.

  • Doppelbock: “Double Bock,” even stronger and richer.
  • Eisbock: Concentrated by freezing the beer and removing the ice, resulting in a potent, syrup-like elixir.

6. International Lagers

  • Mexican Lager: Often uses flaked corn (maize) to lighten the body, served with a lime. Derived from Vienna Lager brought by Austrian immigrants.
  • American Adjunct Lager: The style of Budweiser/Coors. Very light, uses rice or corn, extremely low bitterness.
  • Japanese Rice Lager: Dry, crisp, and incredibly clean, designed to pair with sushi and delicate foods.

The Perfect Pour: The Czech Way

In the Czech Republic, pouring lager is an art form. The amount of “wet foam” changes the flavor profile.

  1. Hladinka (The Smooth): The standard pour. About three fingers of creamy foam. The beer is poured under the foam to keep it fresh.
  2. Šnyt (The Cut): A small beer in a big glass. Two parts beer, three parts foam, one part empty space. Traditionally for the tapster to test the keg, or for a “one for the road.”
  3. Mlíko (Milk): A glass full of wet, creamy foam with almost no liquid beer. It is meant to be drunk in one go and tastes like sweet hop cream.

Sensory Profile

  • Appearance: Usually very clear. Colors range from straw-yellow to deep black. Lagers typically have a thick, white, long-lasting head.
  • Aroma: Clean and focused. Low in fruitiness (esters) compared to ales. You should smell the grain (crackers, bread, toast) and the hops (herbal, floral, spicy).
  • Flavor: Crisp and refreshing. The fermentation byproducts are minimal, allowing the ingredients to shine.
  • Mouthfeel: High carbonation and a smooth, clean finish.

Serving and Glassware

  • Temperature: Best served cold, between 3–7°C (38–45°F). Darker lagers can be served slightly warmer.
  • Glassware:
    • Pilsner Glass: Tall and slender to showcase clarity and carbonation.
    • Steiner / Mug: For heartier styles like Märzen or Dunkel. The handle keeps your hand from warming the beer.
    • Flute: For high-end, delicate lagers.

Food Pairing: A Lager Menu

Lagers are arguably the most food-friendly beers on earth because they cleanse the palate.

  • Starter: Soft Pretzels with Obatzda
    • Pairing: Helles. The breadiness of the beer matches the pretzel, while the carbonation cuts through the rich cheese dip.
  • Main: Wiener Schnitzel with Potato Salad
    • Pairing: Pilsner. The high bitterness and carbonation act like a knife, cutting through the fried breading and fat of the schnitzel, resetting your palate for the next bite.
  • Spicy: Thai Green Curry
    • Pairing: Japanese Rice Lager. The dry, crisp profile refreshes the mouth without competing with the complex spices.
  • Dessert: Apple Strudel
    • Pairing: Doppelbock. The caramel and dark fruit notes of the strong beer harmonize with the baked apples and cinnamon.

Conclusion

Lager is often misunderstood as “boring” due to mass-market examples, but it is actually the most technically demanding style to brew. There is nowhere to hide faults. When brewed well, a lager is a masterpiece of balance and arguably the ultimate refreshment.