Article

Yeast Strains for Belgian Strong Ales

When it comes to making quality homebrew, many factors are important, including sanitation, quality ingredients, proper equipment and techniques. Whatever styles of beer you brew, yeast selection and fermentation management are critical. However, when brewing strong Belgian style ales, yeast selection and fermentation management are paramount since the signature flavors of all Belgian styles are derived from the yeast. To make matters even more complex, there are a large number of yeast strains available to the homebrewer (Wyeast and White Labs offer over a combined 20 Belgian strains), where each one is quite different from the next. But, with a little guidance and a little experimentation, the satisfying quality and complexity of an excellent homebrewed Belgian style strong ale can be enjoyed by each and every homebrewer.

The Belgian Yeast Character

Most of the beers indigenous to Belgium are well known for their unique character, most often imparted by the yeast or bacteria used in their fermentation. Only the Belgian ales brewed using strains of brewer yeast, Saccharomyces cerevisiae, will be discussed here. Beers brewed with wild yeasts and bacteria employ a host of much different strains, fermentation schedules and fermentation characteristics. Also, only the strongest of the Belgian ales will be discussed, those with original gravities exceeding 1.070 including strong golden, tripel, dubbel and strong dark (including a few Trappist ales).

Belgian ale yeasts are noted for the plethora of aromas and flavors that they produce. The two signature chemical families produced by Belgian ale yeasts are esters and phenolics. Esters are noted for their fruity character, often reminiscent of pears, plums, citrus fruits, roses, strawberries, other berries and bananas. Yeast phenolics are often called spicy and many times have the character like the spices of black pepper or clove. However, phenolics that are medicinal, plastic-like or smoky are never appropriate in a Belgian ale. Depending on the style, the esters and phenolics can either compliment or contrast the other flavors found in beer, such as malt, hops and added spices. The biggest trick of the brewer of Belgian style ales is selecting the proper yeast and then taming it to bring out the right levels of each yeast character to suit the beer being brewed.

Coaxing Flavors from your Yeast

When fermenting beers with Belgian strains of yeast, special thought must be given towards many factors to achieve the desired yeast character, specifically the type and level of esters, phenolics and alcohols. Factors such as yeast pitch rate, cool wort oxygenation, fermentation temperature, original gravity, nutrient level and simple sugar content all influence the type and levels of yeast characteristics that each Belgian ale yeast strain will deliver.

Choosing the right fermentation parameters is a balancing act to subtly stress the yeast to give the proper levels of yeast characteristics without going overboard and creating a monster of fusel alcohols and solvent-like characters. Generally, the original gravity of the beer and simple sugar content are fixed for the desired style being brewed. As always, using proper nutrients, such as Servomyces from White Labs, is highly recommended for any style of beer. Therefore, yeast pitch rate, oxygenation level and temperature are the biggest “control knobs” for creating the right yeast character.

Late homebrew author George Fix in his book, “An Analysis of Brewing Techniques” (1997, Brewers Publica-tions), recommended a yeast pitch rate of around 0.75 to 1 million cells per degree Plato and milliliter of wort for ales. One yeast supplier recommends this same rule-of-thumb for Belgian style ales while another suggests slightly less, between 0.5 to 0.75 million cells per degree Plato. To translate that pitch rate to 5-gallon (19-L) batches means that between 165 and 400 billion cells of yeast are needed for 5 gallons (19 L) of Belgian ales at typical original gravities. The table on page 39 can be used to determine the pitch rate and starter size at a compromise between the two main suppliers. For example, for a Belgian ale with an original gravity of 1.080, 284 billion cells are required which can be achieved by making a 0.75 gallon (2.8 L) starter with one Wyeast Activator XL pack or one White Labs tube.

Too low a pitch rate will result in elevated ester levels and which, when too high, can lead to a solvent-like character. Also, low pitch rates can result in high fusel alcohol levels, which are well known for their harsh character, often solvent-like with a burning sensation. Low pitch rates can also lead to slow, stalled, or incomplete fermentations as well as numerous other yeast derived off-flavors such as “green apple” from acetaldehyde or “butterscotch” from diacetyl.

Oxygen is critical for yeast growth. During this phase the yeast will rapidly grow, uptaking oxygen to form sterols, a critical nutrient for the proper development of the yeast’s cell membrane. When oxygen is lacking during this phase, yeast growth is slowed and the cell membrane does not develop the proper permeability. Low oxygen levels can lead to a slow and unhealthy fermentation with an increased level of yeast by-products, such as esters and fusel alcohols. As can be surmised, proper oxygenation is critical when making your yeast starter as well.

Greg Doss, a microbiologist and brewer with Wyeast, recommends that “brewers should use 8–15 ppm of oxygen for healthy fermentations,” but with Belgian ales “12–15 ppm oxygen is recommended.” When brewing strong Belgian ales, two factors impede oxygen dissolving into the cool wort: temperature and specific gravity. Oxygen dissolves more readily at cooler temperatures. Since ales inherently are brewed at higher temperatures, the maximum possible dissolved oxygen is lower than that for lagers. Also, oxygen is less soluble in high gravity worts, making this another barrier for getting proper dissolved oxygen levels in a strong Belgian ale wort. Therefore, it is highly recommended that pure oxygen be used for oxygenating the cool wort for a strong Belgian ale. Doss goes on to recommend that “splashing and shaking the carboy, a traditional homebrew method, only reached 8 ppm of dissolved oxygen where 15 ppm can be reached with pure oxygen and a stone in 80 seconds.”

Controlling the fermentation temperature is necessary for fermenting Belgian ales. The fermentation process is exothermic, meaning that heat is generated by the activity of the yeast. If the temperature of the fermentation is not controlled, the temperature of the fermenter will rise well above the surrounding air by as much as 8.0 °F (4.4 °C). Homebrew yeast suppliers list a recommended temperature range for each of their ale yeasts. But, with a few exceptions, the general recommended starting fermentation range is 68–72 °F (20–22 °C). When fermentation temperatures are elevated, the amount of esters and harsh fusel alcohols produced are increased. For all of the factors that increase esters, controlling fermentation temperature is usually the easiest and most effective. But, if the pitch rate is high (higher than the chart indicates), then the fermentation temperature can be safely elevated, up to the maximum temperature in the yeast’s range. One method that Dr. Chris White of White Labs describes to bring out the character in the yeast is one where “breweries let the temperature free rise which lets the yeast ferment out quickly and creates the flavors that the brewers are looking for.”

Belgian Styles and Their Yeasts

To start, the phrase “Belgian style” is somewhat of an oxymoron since most Belgians do not brew beers to “fit” any particular style; the Belgian brewers mainly focus on brewing what they like and usually it is up to marketing or the consumer to determine what the “style” should be. But, for simplicity of discussion, we must use “styles.” Common style categorizations similar to that of the Beer Judge Certification Program (BJCP, www.bjcp.org) will be used.

Typical of Belgian brewers, any of the yeasts provided by the homebrew yeast suppliers will make a very good Belgian ale if fermented properly. So, feel free to use any type of yeast to make a beer in the true Belgian “non-style.” But, for those homebrewers that want to brew Belgian ales very similar to those classic examples, match the BJCP guidelines or achieve a world-class balance of flavors then this section is for them.

For almost each origin of yeast, one of each strain from the two main homebrew yeast suppliers (Wyeast and White Labs) is listed. Although the reputed origins of a strain from each supplier may be the same, the exact results from each supplier may vary. Each supplier most likely received the strain at different times leading to slight differences between the yeasts. Regardless, based on my experience, the strains for similar origins are much closer to each other than to many of the other strains from each company.

Strong Goldens are known for their strength, usually topping 8.0% ABV (alcohol by volume) as well as for their ease of drink — strong but deceptively so, still light in body and refreshing. The prototypical commercial example is Duvel, but there are many other excellent examples such as Lucifer, Delirium Tremens, Brigand, Avery Salvation and North Coast PranQster. The yeast profile in this style focuses on a marriage of spicy and peppery phenolics with a spicy floral hop character. The ester level is moderate but usually simple, often reminiscent of lemons and oranges, but in a complimenting role.

The primary yeast strains for fermenting a strong golden are Wyeast 1388 (Belgian Strong Ale) and White Labs WLP570 (Belgian Golden Ale) with a probable origin of Duvel Moortgat. These strains produce a strong peppery phenolic with a balanced orange and lemon-like ester. This strain attenuates well but has been known to be slow to ferment and flocculate. At temperatures in the high end of its suggested range, the yeast character can become very estery with a banana character.

Good alternate yeast strains for a strong golden are Wyeast 3522 (Belgian Ardennes) and White Labs WLP550 (Belgian Ale), which are likely from Achouffe. These strains develop a primarily spicy phenolic character with an ester level that stays well in check but with a profile that is more complex than that usually found in a strong golden. This strain can be fermented at higher than normal ale temperatures, around 74–76 °F (23–24 °C), without the esters overtaking the yeast character provided that the proper pitch rate is followed.

Tripels are similar in strength and color to strong goldens but have more of a balance between the fruitiness and phenolic spiciness and with the fruitiness being quite a bit more complex. The malt usually comes through more in the aroma and flavor with more of a body than the strong golden, the difference mainly due to the malt bill and not simple sugar level or attenuation. Excellent commercial examples include Westmalle Tripel, Chimay White (also called Cinq Cents), Affligem Tripel, New Belgium Trippel, Victory Golden Monkey and Unibroue La Fin du Monde.

A few different strains ferment out excellent tripels. First, Wyeast 3787 (Trappist High Gravity) and White Labs WLP530 (Abbey Ale), both reputedly from Westmalle, are excellent choices. Both yeasts produce a predominant ester character, complex and reminiscent of pears, bubblegum, plums and citrus fruits. The peppery spicy phenolic character melds well behind the esters. At higher temperatures, these yeasts can contribute some banana into the ester profile. At low temperatures, lower than 66 °F (19 °C), this yeast can go into a permanent hibernation.

Wyeast 1214 (Belgian Ale) and White Labs WLP500 (Trappist Ale), both possibly from Chimay, also produce very nice tripels. These yeasts produce intense and complex esters, almost indescribable in character due to the complexity. The malt character comes through well and the phenolic spiciness is subdued. Both strains are somewhat slow to start, but attenuate well when given a slightly longer fermentation time. When fermented higher in the recommended temperature range, around 72–76 °F (22–25 °C), the ester character doesn’t significantly change or overpower the yeast character as much as some strains.

Also good for a tripel are Wyeast 3522 and White Labs WLP550, the ester profile is not quite as complex but still quite acceptable. One yeast, relatively new to the homebrew market that would be interesting to experiment with for a tripel would be Wyeast 3864 (Canadian/Belgian) yeast, the reputed source is from Unibroue in Canada.

A Dubbel, unlike the tripel and strong golden, is a dark beer focused on rich caramel and plum-like maltiness with a complimenting complex ester character and a slight contrast of spicy phenolics. The dubbel is not quite a big as a tripel or strong golden at 6–7% ABV but is still big enough to pack a punch. Excellent examples include Chimay Red (also called Premiere), St. Bernardus Prior 8, Westmalle Dubbel, De Konings-hoeven Dubbel, Corsendonk Brown Ale, Allagash Dubbel and New Belgium Abbey.

The best yeast strains to produce an ester character powerful enough to balance the dark malts in a dubbel are the Chimay strains: Wyeast 1214 and White Labs WLP500. The complex esters complement the rich caramel malts (especially from special B) to develop a plum and currant-like character without citrus or banana esters.

One family of Belgian ales, termed Strong Dark by the BJCP, includes a myriad of commercial examples with a range of flavors, all having their dark color and high strength (usually 8–10+% ABV) in common. Strong darks are almost always malty with caramel and toasty characters, but can have any combination of ester and phenolic balance. This style includes the strongest examples of many of the Trappist monasteries. Excellent examples include St. Bernardus Abt 12, Westvleteren 12 (yellow cap), Chimay Blue (also called Grande Reserve), Rochefort 10 (blue), Delirium Nocturnum and Avery The Reverend.

To best replicate the Trappist beers, use a yeast strain that is most likely from the same source as theirs. For replicating the malty and estery Westvleteren and Achel beers, use the Westmalle strains: Wyeast 3787 and White Labs WLP530. Both abbeys received assistance from Westmalle when they began brewing and continue to receive yeast from them on brew day. For malty strong darks with a big complex ester profile, similar to those from the Chimay abbey, use Wyeast 1214 or White Labs WLP500.

For replicating the unique Trappist ales from Rochefort, use Wyeast 1762 (Belgian Abbey II), which reportedly hails from the abbey. This yeast provides a strong spicy phenolic character with a moderate but complex ester profile and a moderate amount of higher alcohols, all very similar in character to the Rochefort beers. But, beers brewed using this yeast benefit from a few months of aging. Other yeasts that are particularly well suited for fermenting a strong dark include the Achouffe strains (Wyeast 3522 and White Labs WLP550).

Brew and Experiment

Once again, these yeast strains are recommended to best produce a beer like the traditional commercial examples or to fall in the guidelines set by the BJCP. In the Belgian tradition, feel free to experiment not only with different strains but with the “control knobs” of yeast pitch rate, oxygen levels, and fermentation temperatures. The suggested starting point is with the pitch rate in the supplied table, 12 ppm dissolved oxygen and a fermentation temperature of 68 °F (20 °C) then adjust as needed to tune your recipe.

In my personal brewing experiences, I tend to slightly underpitch and overoxygenate. Stan Hieronymus, in his book “Brew Like a Monk,” tells of the method of Tomme Arthur (of Pizza Port in Solana Beach, California) where he states that he tends to overpitch and underoxygenate to bring out the flavors in his Belgian influenced ales. So pick your method and tweak it to get your desired results. Split your batches and try a number of different yeasts side-by-side. Consider blending yeasts, as with White Labs WLP575 (Belgian Yeast Blend), which contains two Trappist strains and a additional Belgian strain for ease of use and complexity. Or try some of the newer yeasts out on the market, including Wyeast 3864 (Canadian/Belgian Style), Wyeast 3538 (Leuven Pale Ale) and White Labs WLP510 (Belgian Bastogne). As Chris White says, “be creative and unique, think about what you want first and then build a recipe and fermentation program.”

 

Strain Sources

White Labs and Wyeast don’t officially list the source of their yeast strains. This is because strains change over time and, unless the brewer closely follows the fermentation profile of the brewery — including pitching rates, aeration levels, fermentation temperatures and conditioning practices — he or she will not necessarily get the same profile from the yeast as the commercial brewer did. However, because homebrewers are curious, they have provided some information.

Achouffe — Wyeast 3522 (Belgian Ardennes) and White Labs WLP550 (Belgian Ale)

Chimay — Wyeast 1214 (Belgian Ale) and White Labs WLP500 (Trappist Ale)

Du Bocq (Corsendonk) — Wyeast 3538 (Leuven Pale Ale)

Duvel Moortgat — Wyeast1388 (Belgian Strong Ale) and White Labs WLP570 (Belgian Golden Ale)

Rochefort — Wyeast 1762 (Belgian Abbey II) and White Labs WLP540 (Belgian Abbey IV)

Orval — White Labs WLP510 (Bastogne Belgain Ale)

Unibroue — Wyeast 3864 (Cana-dian/Belgian)

Westmalle — Wyeast 3787 (Trappist High Gravity) and White Labs WLP530 (Abbey Ale)

 

Recipes

Mike’s “Devilish” Belgian Strong Golden (Batch #121)
(5 gallons/19 L, all-grain)
OG = 1.080 FG = 1.015
IBU = 40 SRM = 3–5 ABV = 8.6%

Ingredients

14.7 lbs. (6.7 kg) Belgian Pilsner malt (1.4–1.8 °L)
0.35 lbs. (0.16 kg) CaraPils® malt (6–9 °L)
1.3 lbs. (0.6 kg) granulated corn sugar (15 mins)
7.8 AAU German Perle hops (60 min) (1.0 oz./28 g of 7.8% alpha acids)
2.3 AAU Czech Saaz hops (10 min) (0.75 oz./21 g of 3.0% alpha acids)
1.5 AAU Czech Saaz hops (0 min) (0.5 oz./14 g of 3.0% alpha acids)
Wyeast 1388 (Belgian Strong Ale) or White Labs WLP570 (Belgian Golden Ale) yeast

Step by Step

Mash grains at 150 °F (66 °C) for 90 minutes. Boil wort for 75 minutes adding hops and corn sugar per scheduled times. Cool wort to room temperature and drain or rack the wort off of the trub. Aerate the cool wort and oxygenate. Ferment at 68 °F (19 °C) for 10 days in the primary and 2 weeks in the secondary.

Extract with grains option

Replace Pilsner malt with 3.0 lbs. (1.4 kg) of light dried malt extract, 5.0 lbs. (2.3) light liquid malt extract and 1.65 lbs. (0.75 kg) Pilsner malt. Steep crushed grains at 150 °F (66 °C) in 3.0 qts. (2.8 L) of water. Boil at least 2.5 gallons (9.5 L) and add the liquid malt extract late in the boil.

Dixie Cup Boardwalk Belgian Quadrupel
by Jeff Reilly and Scott DeWalt
(5 gallons/19 L, all grain)
OG = 1.090 FG = 1.020
IBU = 30 SRM = 15–17 ABV = 9.3%

This was the beer that was given to each of the attendees of this year’s Houston Foam Ranger’s Dixie Cup Homebrew Competition. The theme was Fredopoly, based on the board game Monopoly and in honor of our annual speaker and homebrew pioneer, Fred Eckhardt.

Ingredients

12.5 lbs. (5.7 kg) Belgian Pilsner malt (1.4-1.8 °L)
0.25 lbs. (0.1 kg) aromatic malt (17–21 °L)
0.5 lbs. (0.25 kg) dark Munich malt (8–10 °L)
0.75 lbs. (0.33 kg) CaraMunich® malt (80–100 °L)
0.25 lbs. (0.1 kg) special B malt (140–155 °L)
1.0 oz. (28 g) chocolate malt (340 °L)
1.0 lb. (0.45 kg) Belgian dark candi sugar
0.5 lbs. (0.25 kg) turbinado sugar
0.5 g coarsely crushed grains of paradise
0.25 oz. (7 g) coarsely crushed Indian coriander
0.25 lbs. (0.1 kg) chopped raisins
4.5 AAU German Northern Brewer hops (60 min) (0.5 oz./14 g of 9.0% alpha acids)
3.9 AAU German Perle hops (60 min) (0.5 oz./14 g of 7.8% alpha acids)
Wyeast 1214 (Belgian Ale) or White Labs WLP500 (Trappist Ale) yeast

Step by Step

Mash grains at 152 °F (67 °C) for 90 minutes. Boil wort for 90 minutes adding hops per scheduled times and adding spices and sugars at end of boil. Cool wort to room temperature and drain or rack the wort off of the trub. Aerate the cool wort and oxygenate. Ferment at 72 °F (22 °C) for 21 days in the primary and 1 week in the secondary.