Deus: Brut des Flandres

There’s a new kind of beer on the loose. It’s  five years old and unlike any other brew on the market. It’s really a Champagne-like beverage made from wort instead of must (grape juice to be fermented into wine). Perhaps not surprisingly, it comes from Belgium, the land of great brew experimentation; but it also spends part of its cellaring life and undergoes final packaging in neighboring France. The name of this roaming brew is DeuS, Brut des Flandres. (Yes, the brewery spells it with a capital “S.”) The word “deus” is, of course, Latin for God! DeuS is made by the Bosteels Brewery of Bruggenhout, in the Flemish part of Belgium, and it is not cheap. Expect to pay at least $20 for a 750 mL (1 pint 9.4 fl. oz.) bottle.

Bosteels is exceptionally secretive about its DeuS, but the brewery does publicize a few tantalizing hints about its production techniques. The beer is brewed as a strong, blond ale in Belgium and then shipped to the Champagne region of France for bottle-conditioning and packing in accordance with the traditional Champagne-making method, the méthode Champenoise. When applied to beverages other than true Champagne, this process is called méthode traditionelle.

We also learn in the scant product literature that the beer is made entirely from “summer barley, following a unique recipe,” using “techniques developed over centuries of brewing,” and that it is fermented with “specially selected yeast” and aged “on yeast, in the bottle, for months.” The rest of what is knowable about this beer is entirely derived from a much more subjective, but nonetheless equally cryptic source: my taste buds.

The Profile of a Beer Enigma

DeuS has been on the market since 1999. Like a top champagne, it comes in a heavy, solid-looking bottle and should be drunk out of Champagne flutes. The brewery recommends a chilly serving temperature of 2–4 °C (35–39 °F). When poured, it behaves much like great bubbly — brilliantly straw-blond, with a quick-gushing and slowly-receding head.

It has a prickly-pearly, petillant effervescence and — true to its appellation of Brut des Flandres — a very tart and dry, almost sour finish. The beer’s alcohol level of 11.5% ABV is entirely masked by its complex flavor. Like a vintage Champagne, this beer is dated. Recently, I’ve sampled the “Cuvée Prestige 2002”.

The brew’s bouquet is mildly perfumed and faintly malty; its body is light, but not thin. Up front, the palate is stimulated by enticing citrusy notes that are hard to identify on the first sip. The hop notes are gentle and subdued throughout — sharp rather than aromatic, but barely above the taste threshold. There is a second undercurrent of spiciness, which no doubt stems from a small addition of coriander in the kettle.

Not having a brewer’s confession to go by, and not being able to conduct covert industrial espionage, the following is a case of reverse engineering based on the product literature, tasting notes and a few educated guesses.

Grains for the Base Beer

It is a safe bet that the base malt of this Belgian ale is a top-quality 2-row Belgian-style ale malt. A good choice for the clone brewer, therefore, is the pale ale malt from Malteries Franco-Belges, made from barley varieties such as Prisma that grow well in Belgium, Holland and northern France. This barley imparts a slightly malt-aromatic bouquet and produces a highly modified brewer’s grist. If you cannot find the Franco-Belges malt, substitute it with Weyermann Pale Ale Malt, which is also used by many commercial brewers in Belgium.  

Because DeuS has a fairly tart, Champagne-like finish, the remaining 10% of the grain bill should consist of an acidified pale malt, such as Weyermann Acidulated Malt. 

Some who have tasted this beer believe there is wheat in the grist. So, as an option, you can replace 20% of the grain bill with malted wheat. 

Lightly Hopped

The bittering hops is probably a relatively low-alpha, German-style, noble variety such as Tettnanger, or perhaps Perle. The bittering level at the beginning of fermentation is probably around 10 IBU, but the perceived bitterness of the finished beer is much lower because the alpha-acids deteriorate during the brew’s long aging process. There are no aroma hops. 

A Trio of Yeast Strains

In the méthode traditionelle, the beverage undergoes three separate fermentations. Each is probably best served by a different yeast strain. Bosteels may have its own secret fermentation regimen, but this is my method of achieving the same end. 

For primary fermentation, use a relatively clean-fermenting Belgian ale yeast, such as Wyeast 1388 (Belgian Strong Ale) or White Labs WLP570 (Belgian Golden Ale) yeast. For secondary fermentation, use a fairly alcohol-tolerant, crisp-fermenting, well-attenuating and well-flocculating strain, such as Wyeast 3021 (Pasteur Champagne Pris de Mousse) yeast. This will achieve the high alcohol plateau and  produce the dry finish we want. For bottle conditioning, use Wyeast 3347 (Eau de Vie), which can tolerate alcohol levels of up to 21% and thus still do its job under the stresses and pressures of a Champagne-like environment. 

Mash for a Dry Outcome 

The dryness of this beer — along with the line in their product literature about “techniques developed over centuries of brewing” — suggest a multi-step mash, as I’ve outlined in the recipe. However, all these steps may not be necessary given the base malts used. For brewers looking to speed their brewday along, a 30-minute rest at 140 °F (60 °C) can substitute for all the low temperature rests listed in the recipe and still produce a very fermentable wort. For enhanced dryness, the saccharification rest should take place at 149 °F (65 °C) for peak beta-amylase activity. Rest for 30 minutes. Finally, raise the temperature to 172 °F (78 °C) for lautering. 

Boiling for Clarity and Spice

Sparge to a kettle gravity of approximately 1.054 (13.5 °P).  Boil for 75 minutes. After evaporation losses, the gravity should be around 1.060 
(15 °P). Add a single hop loading about 15 minutes into the boil. Add two teaspoons of Irish moss right before and 0.5 oz (15 g) of whole-kernel coriander right after shut down. Let the brew stand for about 30 minutes for better trub sedimentation.

Fermentation for a Clean Base

Heat exchange to around 70 °F (21 °C). Pitch the Belgian ale yeast and aerate the wort thoroughly. Ferment the brew to the finish. Dissolve about 0.2 oz. (6 g) of bentonite (a clay-based fining agent, used in wine production) in about 1 cup of sterile, cold water and add to the beer.  Allow the bentonite and debris to settle, then rack the beer very carefully off this sediment (lees, in winemaking terms). 

Secondary Fermentation 

In order to boost the beer another 5.5% in ABV to reach the target of 11.5%, we need to add 5.0 lbs. (2.27 kg) of fully fermentable sugar to our sparkling beer. We’ll also add Champagne yeast, which is both alcohol tolerant and accustomed to a diet of simple sugars. 

To do this, mix 2 qts. (~2 L) of water and 2.5 oz. (~70 g) of corn sugar (dextrose) or light Belgian candi sugar. Boil to sterilize and then cool. Add the Champagne yeast and 1/8 teaspoon of yeast nutrients. Aerate vigorously. Agitate often to continue aeration over several hours.

Within a day, this starter should be fermenting. Now add twice the amount of sugar (5 oz./140 g), but without aeration. Wait a day and double the sugar addition again, to 10 ounces or 280 grams. Wait another day and add the starter as well as the remaining 3.9 lbs. (1.7 kg) sugar to the brew. Within another day the brew ought to show signs of fermentation. After another two weeks, add a new bentonite mixture — this time with 0.1 oz. (3 g) of the clay. When the brew is still and sedimented, rack it a final time.

Bottling Conditioning 

Make a new 2-qt. (2-L) starter solution, only this time with 1 lb. 
(0.45 kg) of sugar. Add the Eau de Vie yeast, a pinch of yeast nutrients, aerate and wait for signs of fermentation. Let it ferment for one day to give the yeast a good start. Stir the starter into the brew. If necessary, top the brew up with water to about 5 gallons (19 L). Then siphon the beer into about two dozen clean champagne bottles and seal with plastic champagne stoppers and wire cages. 

Finally, place the bottles with the beer-cuvée neck down into wine cartons, at around 15 °C (59 °F), for an almost four-month aging period called  prise de mousse (“taking up foam”). This conditioning is responsible for the all-important bubbles, the sedimentation of the lees into the bottle neck, and the development of the typical méthode traditionelle bouquet that comes from both aging and yeast autolysis. During autolysis, proteolytic enzymes break down dead yeast cells. This aging sur lie (on the lees) enriches the brew with amino acids as well as esters and fatty acids. These trace elements add flavor, bouquet, complexity, and depth to the brew. They also improve CO2 retention and reduce bubble size.

Do the Twist  

After two months of the prise de mousse, start riddling the brew (remuage). This involves twisting each bottle sharply one-quarter turn with the flick of the wrist once each day for two weeks. This helps to lodge all the sediment in the neck. Then leave the brew undisturbed for another month.

Yeast Out, Dosage In 

Now comes the trickiest part of the méthode traditionelle operation, the removal of the sediment, which is usually accompanied by a loss in beer volume — perhaps as much as 50–100 mL (1.7–3.4 fl. oz.) per 750 mL bottle. So the first thing to prepare on the day of dégorgement (disgorgement) is the replenishment, called the dosage.

Champagne makers usually dissolve about 600 g of sugar in one liter of dosage to make a syrup. We will boil some light dried malt extract (DME) in water instead. You might need about 2.4 L (82 fl. oz.) of dosage and thus 
1.5 lbs. (0.68 kg) of DME. Chill the dosage before using. Next, place the inverted bottles into your freezer. Keep them in their cartons if possible. Carefully monitor the freezing progress. The neck sections will freeze first, but do not let the entire bottles freeze as they will burst! 

The next step is messy and best done outside. While holding the frozen bottle upside-down, remove the wire cage and let the bottle pressure slowly push out the plastic stopper, at which point the sediment will pop out, too. Now quickly (very quickly!) close the bottle with your thumb and turn it right side up. Top the bottle off with the dosage and close it with a fresh plastic champagne stopper and wire cage. 

In a commercial facility, nowadays, the necks are flash-frozen in a solution of glycol at -11.2 °F (-24 °C) and the dégorgement is accomplished with the bottles standing right side up.

The beer called “God” should be ready for your palate after the ordeal of the dégorgement process after a month of calming down in your cool, dark basement. 

Use only genuine Champagne-rated bottles with a deep punt in the bottom. If you are not sure that yours are real Champagne bottles, don’t use them. At up to 100 PSI pressure inside, an exploding bottle is like a shrapnel grenade and can cause serious injuries. Always wear thick gloves, a full-face safety mask and a thick coat while handling closed Champagne bottles. This is not an overly-cautious safety recommendation for the timid; you are virtually assured to be injured — probably badly — if a bottle explodes in your hands and you are not properly protected.  

You may skip the entire dégorgement, of course, by simply bottle conditioning the brew right side up. When you are ready to drink it, simply open it carefully and pour the entire content slowly, but in one swoop into a row of champagne flutes, leaving about 0.5–2 inches (1.3–5 cm) of sediment behind to be discarded.

In this article, I present an adapted version of the méthode traditionelle for making this beer. For a highly informative and well-written explanation of the traditional méthode champenoise, see “A Review of Méthode Champenoise Production” by Bruce Zoecklein, Associate Professor and Enology Specialist of the Department of Food Science and Technology at the Virginia Polytechnic Institute, at For a good explanation of the techniques for making sparkling wine at home, see Tim Vandergrift’s article “Making Sparkling Wine from Kits” in WineMaker magazine (April–May 2002).

DeuS clone
Brouwerij Bosteels, Belgium

(5 gallons/19 L, all-grain)
Virtual OG = 1.102  FG = 1.012–1.014
IBU = 8  SRM = 5–6  ABV = 11.3–11.6%

11 lbs. (5.0 kg) Belgian pale ale malt
1.1 lbs. (0.50 kg) Weyermann acidulated malt
5.0 lbs. (2.27 kg) dextrose (corn sugar) or light Belgian candi sugar
2.25 AAU Tettnanger hops (60 min.) (0.5 oz./14 g of 4.5% alpha acid)
0.5 oz (15 g) whole-kernel coriander
2 tsp Irish moss
0.35 oz. (10.5 grams) bentonite
Wyeast 1388 (Belgian Strong Ale) or White Labs WLP570 (Belgian Golden Ale) yeast
Wyeast 3021 (Pasteur Champagne Pris de Mousse) yeast
Wyeast 3347 (Eau de Vie) yeast
1.0 lb. (0.45 kg) corn sugar (for priming)
1.5 lbs. (0.68 kg) light dried malt extract (for dosage)

Step by Step
Multi-step mash base malts for 60 minutes at 100 °F (38 °C), 15 minutes at 113 °F (45 °C), 30 minutes at 122 °F (50 °C) and 30 minutes at 149 °F (65 °C). Mash out to 172 °F (78 °C). Sparge with 170 °F (77 °C) water and collect 4.5 gallons (17 L) of wort. Boil for 75 minutes, adding bittering hops with 60 minutes remianing in boil. Cool wort, aerate and pitch Belgian beer yeast. Ferment at 70 °F (21 °C), then fine with bentonite. Secondary fermentation: Make sugar solution and mix into wort with Champagne yeast. Fine with bentonite when secondary fermentation is complete. Tertiary fermentation: Make second sugar solution with 1.0 lb. (0.45 kg) sugar and stir into beer with Eau de Vie yeast; siphon into Champagne bottles. Age beer for 2 months. Packaging: Proceed with riddling and disgorgement (as described in the May-June 2004 issue of Brew Your Own). Alternately, you can skip this step and simply bottle condition the beer. Serve at 36–39 °F (2–4 °C) in a Champagne flute.

Extract only option: Extract brewers can replace the pale ale and acidulated malt with 8.3 lbs. (3.76 kg) of liquid malt extract or 6.75 lbs. (3.06 kg) of dry malt extract. Skip the mashing process outlined above, dissolve the malt extract in water and begin brewing at the boiling stage.

Issue: May-June 2004