by Roger Bergen
The uniquely American hybrid that launched the microbrewery revolution has always been poorly understood. Made by using a lager yeast... at ale temperatures... in odd fermentors... it must be from San Francisco!
As most readers know, the term Steam Beer is the registered trademark of the Anchor Brewing Company. This is only fair: Anchor was not just the sole steam beer brewery to reopen after Prohibition but was the country's first microbrewer long before the term was coined, has been the pioneer of the craft brewing industry and inspirer of many microbrewers and home brewers, and continues its avant-garde work in interesting beers. Of course, microbrewers can, and sometimes do, work in this style, as do home brewers. The recognized term for the style is now "California common beer," an accurate, if pedestrian, appellation. Because this article takes a historical perspective, I use the term "steam beer."
Volumes have been written in both the specialist and general press about the successful revival of this once-moribund style, so as usual this article first examines the origins of the style, how it was once brewed, and some differences evident in modern Anchor Steam Beer. Once again, the Wahl-Henius American Handybook of the Brewing, Malting, and Auxiliary Trades from 1908 provides key insights because it contains the only known description of steam beer brewing in its pre-Prohibition heyday. The account in the accompanying box is not a portrait of Anchor before 1965, but a broad picture of steam beer brewing when the style was practiced by perhaps 25 brewers in San Francisco alone. It is unknown whether this account was written from first-hand observation of steam beer breweries or from second-hand information.
The Wahl-Henius account raises a number of interesting points. Although it presents steam brewing in its most developed form some 40-50 years after its obscure birth, the overall impression is one of rough-and-ready frontier brewing. The equipment is simple and inexpensive, and the beer is not tied up in long, costly aging. The process seems to be a hybrid of British and Continental (prelager) brewing practices allied with the then-fashionable bottom-fermenting yeast, with a dash of Californian ingenuity thrown in for good measure. Simple brewing like this must have been practiced by brewers, both native-born and immigrant, who traveled with their copper kettles and wooden vessels to the next greener pasture or boom town across the Wild West. The most noteworthy feature of steam beer was its high carbonation, but otherwise the narrative raises as many questions as it answers, leaving us to piece together the answers.
Either "roasted malts," presumably caramel and/or black malts, or caramel coloring were used. What is unclear is the meaning of "the favored amber color of Munich beer." This might have been the amber of Mrzenbier but is more likely the deeper color of Mnchner dunkles; otherwise the color would have been compared with that of Vienna beer. Modern Anchor Steam uses caramel malt to achieve its copper Viennese color.
The use of adjuncts was probably uncommon. Wahl and Henius were great advocates of adjunct brewing, which they felt was the key to chill-stable bottled beer (the adjuncts dilute the protein and tannin content). At the time, however, adjunct brewing was only about 30 years old, and most Eastern and Midwestern brews for local draft consumption were still all-malt. We have no reason to believe that conditions were any different in San Francisco in this regard, and brewhouses designed for raw adjunct use are on the whole more expensive and complex than the relatively simple plant most steam beer brewers would have possessed.
The hops used would have been almost exclusively California hops, primarily from the Russian River growing area, which at the time was the prime hop growing region in the United States (1). Downy mildew pushed hops out of the Russian River area completely by the late 1950s, but one farm hung on near Sacramento in the Central Valley until the mid-1980s. California hops were a variant of Cluster, and Russian River hops in particular were considered to be of very fine quality. My own experience with Sacramento hops confirms their excellent quality and finer flavor and aroma than modern Yakima Clusters. The role of a-acids in brewing was just being discovered in 1908, when chemical analysis was in its infancy. The only analysis provided in Wahl-Henius gives 4.7% a-acid resins and 8% b-acid (1), which we can use to arrive at a typical bitterness for steam beer. At the recommended 12 oz/bbl, added all at once at the beginning of the boil, we get about 40 IBU; added in three equal increments during the boil we get about 28 IBU. Alpha yields were highly variable, however, and although the benefits of refrigerated storage of hops were known, refrigeration was not widely used. Modern Anchor Steam uses whole-leaf Northern Brewer hops at about 0.5 lb/bbl, some of them added late for aroma, and has a bitterness of 30-35 IBU.
San Francisco has always had soft water. Well water from the San Francisco Presidio is reported to be soft with some sulfate -- perhaps 50 mg/L calcium -- and well water similar to this was the original water for steam beer. At the time Wahl and Henius were writing, the Hetch Hetchy water system had just come on line, supplying the city with extremely soft snowmelt water from the Sierras; today this water has a total dissolved solids content of 15 mg/L.
Brewhouse Process and Equipment
After hop separation in a hop back, cooling began in the surface cooler, also known as a "coolship," a wide, shallow vessel of copper or iron (1,2). Better-equipped breweries would have had a Baudelot cooler (1). This was a completely open heat exchanger in which the wort was trickled over a series of horizontal pipes carrying coolant, aerated by its splashing as it went, then collected in a pan at the bottom and sent to the fermentors. Anchor now uses a whirlpool tank and a plate heat exchanger with injected aeration.
Fermentation and Yeast
Enter the clarifier, unique to steam beer breweries. Some unknown brewer must have been inspired by the coolships used for wort cooling; perhaps the first clarifiers were coolships pressed into service for fermentation. The great surface-to-volume ratio of these vessels allowed the heat of fermentation to simply dissipate into the air. Another benefit, and possibly the root of the name, is that yeast would have settled quickly in the shallow vessels, enabling the beer to be racked immediately for quick consumption. Because bottom-fermenting yeasts do not form a protective "pancake" on the surface as true ale yeasts do, constant skimming must have been essential to remove airborne contamination before it could fall into the beer. Anchor still practices skimming to remove cold trub and hop resins. Although the use of starting tubs was universal in all breweries in the old days, Anchor now runs the cooled wort directly into beautiful stainless clarifiers, housed in clean rooms that are supplied with sterile-filtered, positive-pressure air at ambient San Francisco temperature.
The yeasts required to make this fermentation system work needed special characteristics. First, they would have to produce acceptable flavors at temperatures that were far higher than normal for lager yeast at the time. Second, they would have to remain in suspension long enough in the extremely shallow vessels to complete fermentation, then settle quickly. Third, it was essential that the yeast cooperate with the finings to create a firm sediment in the kegs; unfortunately lager yeasts have generally poor attraction to finings compared with ale yeasts, and many lager strains are unaffected by isinglass (gelatin finings prepared from calf hide were known; see reference 1). Given the demands made on the yeast and the primitive conditions, I suspect that yeast problems were common in steam beer breweries.
The source of Anchor's present yeast strain is a deep mystery. Those wishing to make a California common beer in conventional fermentors will find many suitable modern lager strains with good high-temperature performance. I recommend Weihenstephan 34/70 (Wyeast #2124) and Wissenschaftliches #308 (Wyeast #2308).
The large number of actively fermenting yeast cells and the high pressure may have given some protection from wild yeast and bacteria for a while. On the other hand, until the beer had been cellared for a week or two, considerable acetaldehyde, diacetyl, and hydrogen sulfide must have been present -- the usual primary-fermentation characters associated with kraeusened beer, although warm storage temperatures would have hastened their reduction.
Pouring steam beer in a saloon must have been a chore far beyond that associated with today's product. I theorize that a slow, careful "German" pouring style must have been used, resulting in a billowing head and gentle carbonation in the mouth. Many volatile green-beer compounds would have been blown off by the excess carbon dioxide during the pouring. It was, in its first life, a rough-and-ready working man's beer and must have been especially enjoyed by the many English, Irish, and German immigrants who built the turbulent city by the bay.
This process was essentially unchanged in 1965 when Fritz Maytag took over Anchor Brewing. Even after sanitation and process control were improved, Anchor realized that the market required a stable and consistent beer and gradually introduced modern processes. Modern Anchor Steam has about 10-15% kraeusen, is cellared at cold temperatures for three weeks, centrifuged, polish filtered, and flash pasteurized before bottling. Carbonation is still high, at approximately 2.8 volumes for draft Anchor Steam and 3.0 volumes for bottled beer. Despite concessions to the modern world, Anchor Steam Beer remains both distinctive and authentic.
Let us thank the gods of brewing that Anchor Brewing survived long enough for a young Stanford graduate to let the whole world in on a great thing.
(2) R. Barchet, "Hot Trub: Formation and Removal," BrewingTechniques 1 (4), 38-41 (1993).
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