California Common: The Industrial Hybrid of the West

In the landscape of beer styles, the California Common (famously known as “Steam Beer” by the Anchor Brewing Company) stands as a unique biological and historical anomaly. It is one of the few truly American beer styles that predates the craft revolution, born out of the necessity and ingenuity of the California Gold Rush era in the late 19th century.

To the technical brewer, the California Common is a study in Thermal Adaptation. It is a beer brewed with Lager Yeast but fermented at Ale Temperatures. This hybrid process creates a profile that is unlike anything else: the crisp, clean finish of a lager combined with the fruity esters and “rustic” character of an ale. This guide explores the Kinetics of Warm Lagering, the Woody Chemistry of Northern Brewer Hops, and the Legacy of San Francisco Steam.

1. History: The “Steam” of San Francisco

During the 1850s, San Francisco was a boomtown without a cold-storage infrastructure. Ice was a luxury that had to be shipped from Alaska or the Sierra Nevada mountains. The German brewers who flocked to California wanted to brew their traditional lagers, but they lacked the refrigeration required for the cold fermentation and long lagering of the Old World.

1.1 The Hybrid Solution

Resourceful brewers discovered that certain lager yeast strains could tolerate being fermented at ambient temperatures (15°C - 20°C).

The Name: The term “Steam Beer” likely refers to the high pressure of carbonation in the barrels (which let off steam when tapped) or the “Steam” rising from the open cooling trays (coolships) on the San Francisco rooftops, cooled by the chilling Pacific fog.
The Anchor Legacy: While many breweries made “Steam” beer, Anchor Brewing preserved the style in the 1960s and 70s, eventually trademarking the name “Steam Beer,” which led to the BJCP style designation of “California Common.”

2. Technical Profile: The Warm Lager Paradox

The defining technical feature of the style is the behavior of the California Lager Yeast (White Labs WLP810 or Wyeast 2112).

2.1 Fermentation Kinetics

Unlike standard lager yeast (like 34/70) which produces heavy sulfur and “stressed” flavors at 20°C, the California Common strain is remarkably stable.

ESTERS: At 18°C, this yeast produces a mild “fruitiness”—typically light pear or apple—that is absent in cold-fermented lagers but subtler than what you find in an IPA.
SULFUR: It maintains the ability to “Scrub” sulfur even at high temperatures, resulting in a cleaner profile than a typical ale.

2.2 The “Rustic” Malt Synergy

The malt bill is built on American 2-Row and Crystal 60L.

The Maillard Logic: The use of medium-to-dark crystal malt (8-10%) provides a toasty, caramel sweetness. This “Rustic” maltiness is the perfect partner for the slightly fermented fruitiness of the yeast. It is a beer that tastes “Brown” and “Toasted” without being heavy.

3. The Ingredient Deck: The Northern Brewer dominance

3.1 The Hop: Northern Brewer (The Woody King)

The California Common is perhaps the only style defined by a single hop variety: Northern Brewer.

The Chemistry: Northern Brewer is high in a terpene called Humulene.
The Perception: In this style, it is perceived as “Woody,” “Evergreen,” and “Minty.” It provides a firm, structured bitterness (30-45 IBU) that cuts through the caramel malt sweetness.
The Strategy: Use Northern Brewer for the 60-minute bittering and a significant 15-minute addition for that signature “forest” aroma.

3.2 The Water: Moderate Carbonate

San Francisco water historically had moderate alkalinity.

Technical Tip: You want some Calcium Carbonate to buffer the acidic crystal malts. Aim for a “Balanced” water profile—moderate sulfates for hop pop, and moderate chlorides for malt roundness.

4. Recipe: “The Yerba Buena Steam” (5 Gallon / 19 Liter)

OG: 1.050
FG: 1.012
ABV: 5.0%
IBU: 38
Color: 12 SRM (Amber-Copper)

4.1 The Mash and Boil

Saccharification: 67°C (153°F) for 60 minutes. We want a “medium” body—enough to support the crystal malt but dry enough for high drinkability.
The Boil: 60 minutes. Focus on the 15-minute Northern Brewer addition for flavor.

4.2 Fermentation: The “Intermediate” Temp

Pitching: Pitch at 15°C (59°F).
The Rise: Let the temperature rise naturally to 18°C (65°F) as the fermentation proceeds. This “Limited Rise” is what captures the ester profile without letting it become “funky.”
Conditioning: Unlike a true lager, which needs 8 weeks, a California Common is usually ready after 3 to 4 weeks of conditioning at 10°C.

5. Advanced Techniques: The “Coolship” Mimicry

Professional brewers of California Common often use Shallow Fermenters.

The Physics: A shallow, wide fermenter increases the surface area relative to the volume. This encourages the release of volatile sulfur compounds and results in a more efficient heat dissipation, mimicking the Rooftop Cooling trays of old San Francisco.
Homebrew Hack: If you use a standard bucket or carboy, don’t wrap it in insulation. Let it breathe to simulate that industrial heat loss.

6. Troubleshooting: Navigating the Fog

”The beer is too fruity; tastes like a Belgian Ale.”

Your fermentation temperature was likely too high (>21°C). At these temperatures, even the California Lager strain will produce excessive esters. Ensure you stay in the “Goldilocks” zone of 15°C - 18°C.

”It tastes ‘Dusty’ or ‘Musty’.”

Northern Brewer can sometimes lean toward “Earthy” in a negative way if the hops are old or oxidized. Always use fresh, nitrogen-purged pellets to ensure you get the “Woody/Minty” notes rather than “Dry Dirt."

"No Head Retention.”

California Commons are highly carbonated. If your foam is weak, ensure you have a clean “Hot Break” in your boil and consider adding 5% Flaked Barley or Carapils to provide the necessary proteins for a long-lasting head.

7. Service: The Working Man’s Amber

Glassware

The Standard Pint Glass or a Beer Mug.

Serving Temp: 6-10°C (43-50°F). It should be served warmer than a Pilsner but cooler than a British Bitter.

Food Pairing: The California Cuisine

Sourdough Bread and Dungeness Crab: A classic San Francisco pairing. The “tang” of the bread and the salt of the crab are balanced by the beer’s caramel malt and woody hops.
Grilled Burgers: The caramel notes in the beer match the seared crust of the meat perfectly.
Aged Gouda: The nutty, toffee notes of the cheese mirror the “rustic” malt profile of the 12-SRM amber ale.

8. Conclusion: The Beauty of the In-Between

The California Common is a celebration of the “Middle Ground.” It is not quite a lager, and it is not quite an ale. It is a technical demonstration of how a single yeast strain, when pushed out of its comfort zone, can create something entirely new.

By mastering the Warm-Lager fermentation and respecting the Woody chemistry of Northern Brewer, you are brewing a piece of American history. You are capturing the spirit of the 1850s boomtown—a beer that is as rugged, ingenious, and refreshing as the city of San Francisco itself.

Curious about other hybrid styles? Explore our Cream Ale Brewing Guide.