Brewers Association

Style Spotlight: Imperial Russian Stout

Style Spotlight: Imperial Russian Stout

Style Spotlight: Imperial Russian Stout

By Tim O'Rourke

With the Industrial Revolution came the birth of regional breweries serving a wider community and a new beer style called porter, which became the beverage of choice for the new, more affluent members of the urban population.

Brewing in those days was quite different from today, with large mash tuns serving a range of smaller wort kettles (coppers) whose maximum size was restricted to 200 barrels to ensure suitable heat transfer when using direct wood or coal firing. With a number of separate kettles all with different wort densities, it allowed the brewer to produce a range of different products with different original gravities from the same brew, called parti-gyles.

High gravity or strong porters produced from the strong worts from the first runnings of the mash tun were called stout porters, and hence the derivation of stout today.

London was the historical home of porter brewing. Barclay Perkins Brewery (which bought the former Thrale brewery in 1781) supplied their Extra Stout to a Belgian merchant called Albert Le Coq. He, in turn, bottled it under his own label and shipped it to the Baltic, including St. Petersburg and other Russian cities. Legend has it that a fortunate gift of 5,000 bottles to the Russian military hospitals was rewarded with an Imperial Warrant of Appointment, and Imperial Extra Double Stout was born.

Le Coq was later invited to brew this legendary beer within the Russian Empire. In 1912, production commenced in Tartu, now Estonia.

Courage and later Scottish and Newcastle continued to do the occasional brew of Imperial Stout, but it had been relegated to the pilot plant and is really only used for internal tasting.

Qualities of Imperial Russian Stout

Russian stout uses a high percentage of colored malts. Stouts and porters were originally brewed with brown malt, which still had some enzyme capacity. However, more recently the production of enzymic brown malt ceased, and the grist was replaced with pale malts to provide the diastatic power, and dark and roast malt to provide the color and flavor.

The beer has a high alcohol content around 10 percent, and a very high hop rate estimated at 150 IBU. The hop rate has been substantially reduced to meet current consumer preferences. The stout was fermented at a high temperature and held in vats for over a year. With high alcohol and hop rate (providing antiseptic properties), the beer is robust and has good keeping qualities. Samples of Imperial Stout over 20 and 30 years old are still drinkable today.

Recipe for Imperial Russian Stout (based on the Barclay, Courage Simonds recipe of the 1970s)

Analytical Specification for Imperial Russian Stout

  Target ASBC
Original Gravity 25° Plato
Final Gravity 6.0° Plato
% alcohol v/v 10.1%
pH 4.0 units
Bitterness 55 IBU
Color 145 Lovibond
Carbonation 2.5 volumes

Harveys of Lewes Brewery was asked to take up the challenge of brewing authentic Russian Stout. They sought advice from Le Coq, who provided details of their porter style beers. Miles Jenner, the managing director of Harveys, kindly shared these recipe details with me.

Water

They found that the spring water used to brew Harveys of Lewes was similar to that used by Barclay Perkins Brewery in Southwark. Tables in A.J.B. Scholefield's The Treatment of Brewing Water (1955) showed similar levels of calcium carbonate, at 162 ppm and 148 ppm respectively, and calcium sulfate levels of 20 ppm and 19 ppm. In addition, the old well had seen sodium chloride levels in excess of 200 ppm with seasonal fluctuations, the Southeast London water being quoted at 248 ppm.

Scholefield stated that for stouts and black beers, the waters most suitable were "those with fair amounts of calcium and magnesium carbonates, with some chlorides, but sulphates in no large amount."

The water treatment required (all based on producing 1 U.S. barrel [31 gallons])

Water Treatment

Weight grams Weight oz
Calcium sulfate CaSO4 (gypsum) 10 grams 0.35 oz
CaCl 10 grams 0.35 oz
Boiling or acid dosing (phosphoric acid) To give total alkalinity < 70 ppm as CaCO3

Note: It is recommended that brewing water is boiled before use if it is highly chlorinated or has high temporary hardness (calcium bicarbonate).

Malt

Harveys' recipe was complemented by the recollections of brewers who had produced Barclay Perkins Russian Stout in the 1950s. The resultant brewsheet comprised a grist of 62.5 percent pale ale malt and 37.5 percent colored malts—a combination of amber, brown and black. This was supplemented with invert sugar in the copper, which ultimately contributed 15 percent of raw materials by weight and around 20 percent of the wort composition.

This recipe is similar to that used by Courage at Park Street in the 1970s and probably is a reasonable representation of earlier versions of Russian Stout.

Malt and Extract Grist Required (based on producing 1 U.S. barrel [31 gallons])

Extract Grist % inclusion Weight (kg) Weight (lbs)
Pale malt (well modified ale malt) 60 % 25 56
Amber malt 24 % 11 26
Black malt * part added to copper 3.5 % 2 4.4
Cane or invert sugar 12.5 % 7 12.8

* 0.05 lb (0.02 kg) of black malt was added directly to the copper

The 1970s brew used glucose syrup, but the original brew probably used semi-refined cane sugar imported from the Empire, which would have helped achieve the required original gravity and gives beer a luscious fullness.

For brewers who would prefer to get all their extract from malt, the grist could be amended to use 60 lbs of pale malt, 36 lbs of amber and brown malt, and 3 lbs of black malt. This is a recipe for Old Ale from the Durden Park Beer Club Recipe book, but very similar in style to Russian Stout.

Hops

The original beer would have had a high level of bitterness. For modern tastes, a bitterness between 50 and 100 BU should be used depending on personal preference. It seems probable that all the hops were added at the start of a three-hour boil, using favored British hop varieties such as Fuggles and Goldings with around 5 percent alpha acid. Hops were added for bitterness only and the beer would have little if any hop aroma character. Later this was changed to give hop aroma.

Hop Grist Required (all based on producing 1 U.S. barrel [31 gallons])

Hop Grist Assumed Bitterness % alpha acids Target final bitterness Grams of hops Pounds of Hops
UK varieties 5 % 50 BU 0.5 kg 1 lb 2 oz
Fuggles & Goldings 5 % 100 BU 1.0 kg 2 lb 4 oz

Brewing Procedure

The brewing procedure used at Park Street was very complex, involving a series of hot sparge and underlets designed to change the mash stand temperatures and to aid in extracting the flavors from the malt. A simpler mashing regime based on that used by Harveys is recommended with a mash stand temperature of 152° F (66.5° C) for 90 minutes. The grist is mashed at a ratio of 1 part grist to 2 parts water (30 gallons or 113 liters).

At the first extract during first wort, the runoff should exceed 1.100 or 25° Plato. Approximately 30 gallons (115 liters) of sparge is then added sparingly at a temperature of 170° F (76° C). With a final collection of around 50 gallons, make sure the original gravity does not fall below 1.080 (19° Plato). This is particularly important when brewing the all-malt variant.

When this beer was produced in Park Street, it was brewed alongside Velvet Stout (OG 1.040 [10° Plato]) to use the rest of the weak worts. If cane sugar is used, it may be possible to add more sparge while still maintaining the required collection gravity.

Wort collection is followed by a three-hour boil with hops added in three equal parts at hourly intervals in equal proportions. The cane sugar can be added as soon as the wort starts boiling to aid dissolution and prevent burning. With around 10 percent evaporation per hour, the gravity should increase from 1.080 (19° Plato) to around 1.104 (25° Plato). The hot wort should be filtered through a hop back and there are plenty of hops to act as a great filter bed.

The wort should be cooled to 60° F (15° C) and pitched with 2.0 lb of ale yeast slurry which is known to be osmo-tolerant (around 1 lb dry weight if using dried yeast). The wort needs intensive aeration and air or oxygen should be added at collection. It will probably be necessary to aerate again or agitate twice after 14 and 28 hours to stimulate yeast growth.

The temperature should increase naturally to around of 82° F (27° C) after 64 hours when it should be skimmed. The gravity should have reached 1.045 (11.2° Plato) with a top heat of 82° F (27° C). The gravity should continue to fall slowly over the next 60 hours to reach around 1.030 to 1.035 (7.5 to 8.5° Plato) When this has been achieved, remove what yeast is left and transfer to storage.

The green beer should be stored at 60° F (27° C) and the vessel vented daily until the secondary fermentation has largely ceased. If hop aroma character is required, then dry hops at the rate of 8 ounces of Styrian Goldings per barrel can be added at this stage. The beer should be warm conditioned until the final gravity of 1.025 (6.3° Plato) is achieved.

The beer was generally matured in oak vats. It is said that Russian Stout for the domestic market was taken out of bond and rolled around the yard each month to "simulate the effect of the treatment it would have received in transit to the Baltic." If true it is a good way of keeping yeast in suspension. It is at this stage that Brettanomyces claussenii could be added if required. In the 1800s to 1900s the beer would have naturally contained a range of microorganisms along with brewers yeast Saccharomyces cerevisiae, with additional infection being picked up from the storage casks. Harveys Brewery found that their own brewing yeast strain has a low infection of Debaromyces hansenii, which does not manifest itself in their main brands but is only noticeable after a long lag phase, where it contributes to the final flavor of the beer. The choice of whether to add any "deliberate" infection is personal and difficult to control. It may add a unique character and taste or may only serve to ruin a great beer.

Once the target final gravity is achieved, the beer should be cooled for a week and excess yeast removed. Yeast counts should fall to 1-2 million cells per milliliter with the formation of a tight sediment in the storage tank. The supernatant beer should be transferred or the sediment removed and an optional 20 ppm SO2 added as a preservative. The beer should be roused and then bottled.

The beer is best stored for a year before consumption, and a secondary fermentation in the bottle will add to the natural condition in the beer.

Flavor Descriptors

  • The beer should be black, smooth and creamy with a strong brown/cream foam.
  • The aroma is of burnt roasted caramel/chocolate maltiness and warming dark fruit aroma like a good port or sherry.
  • It has a sweet taste with roast and dark chocolate notes with caramel licorice flavor. It can be spicy and fruity.
  • Mouthfeel and aftertaste is sweet, full and velvety with a slight astringency from the black malt and bitter hops.
  • If late hops are used, there will be a light citrus hop aroma.

Conclusion

Imperial Russian Stout is a king amongst beers, delivering flavor, passion and subtlety. Harveys in Lewes has produced a very good example against which other brews can be judged. Their 1999 vintage Imperial Stout won a gold medal at the Brewing Industry International Awards after it had been in the bottle for two years. They also received the accolade of World’s Best Imperial at the recent World Beer Awards organized by Paragraph Publishing and Beers of the World magazine.

Britain's Tim O'Rourke is director of the Brilliant Beer Company, one of the brewing world's largest training schools.

References

  1. Harrison, John. Old British Beers and How to Make Them. Durden Park Beer Circle.
  2. Pudney, John. A Draught of Contentment: The Story of the Courage Group. New English Library, 1971.
  3. Hornsey, Ian. A History of Beer and Brewing. RSC paperback, 2003.
  4. Jackson, Michael. The New World Guide to Beer. Mitchell Beazley, London 1997.
  5. Jenner, Miles. "Beer with Extraordinary Style" talk given at Harveys Brewery, Lewes, April 2008 to the Institute of Brewing & Distilling Southern UK Section.
  6. Jenner, Miles. personal communication.
  7. Noble, Stuart. Brewers black notebook dating from late 1970.
Photo © 2010 istockphoto.com
Btn_back

No comments.

Zach Yunker

Zach Yunker

General manager of Sockeye Grill and Brewery in Boise, Idaho. More