Flemish Red-Brown Beer

Flemish red-brown beer, also known as "Flanders red brown beer" or simply "Flemish brown beer" , is a classic Belgian beer style that is produced only by a small handful of breweries in Flanders, Belgium today. Some breweries outside of Flanders and Belgium aim to produce comparable beers . These beers, red to brown in color, are characterized as being sour and sometimes sweet, with malt flavors and fruity complexity from the mixed fermentation and sometimes hints of oak. They have often been described as "wine-like". Non-Belgian beer writers, beginning with Michael Jackson, have split these beers into two categories: "Flanders Red Ale" and "Oud Bruin". The distinction between these two has arguably been that "Flanders Red Ales" are generally brewed in West Flanders and are aged in oak, while "Oud Bruin" is generally aged in steel fermenters and brewed in East Flanders, and the "Oud Bruin" version is less acetic and more malty in flavor (Belgian brewers make no such distinctions). Rodenbach, Brewery Verhaeghe, Liefmans, and De Brabandere are examples of some of the most well known Belgian producers . Classic Belgian examples have been flash pasteurized or sterile filtered and are not alive in the bottle (~35 minutes in) (also ref Mad Fermentationist dregs list). Belgian brewers are seeking to protect the term "Flemish Red Brown Beer"; see Protection Seeking below.

History

A brief history of Flemish-Red-Brown Beers by Roel Mulder of Lost beers blog.

For all we know, Flemish brown as a beer style is not that old. Only a few early 19th century sources mention something that resembles it and the first real description of the 'bitter, rough and astringent brown beers of Flanders' dates from 1851.

Before the 19th century, most beer in today's Belgium was drunk fresh and was not allowed to age for more that maybe a couple of months at most. However, during the 18th century a few keeping beers developed in Western Europe, such as porter in Britain, a beer called 'old brown' in The Netherlands, and faro and lambic and Brussels.

Apparently, the brewers of Flanders (by which we mean: today's Belgian provinces of East- and West-Flanders) were late adopters. It wasn't until ca. 1880 that their aged, brown beer really became popular. The Rodenbach brewery in Roeselare, founded in 1825, may have played a role in this. Around 1875, young Eugène Rodenbach worked as an apprentice in various breweries in England, and allegedly he used some the knowledge he acquired there to introduce new working methods at the brewery in Roeselare.

Around 1900, old brown beer was very popular everywhere in the province of West-Flanders, while in East-Flanders it was the city of Oudenaarde that became most famous for it. Many drinkers and brewers compared it to wine. Rodenbach advertised with 'It's wine!', while Den Os brewery in Bruges simply sold their old brown as 'Bourgogne des Flandres' ('Burgundy of Flanders'). Especially after 1945, the Belgian beer market saw an increasing trend of consolidation. Bottom-fermented beers, especially pilsener, where increasing their market share. Sales of old brown beer were dropping. Various producers made their beer slightly sweeter and less sour to appeal to younger customers. Liefmans in Oudenaarde is a well-known example, but in 1974 even Rodenbach announced they were 'softening' the taste of their beer.

During the 1970s, the more traditional beers of Belgium started to be better appreciated. An important factor in this was Michael Jackson's influential 1977 book The world guide to beer. Contrary to local customs, Jackson chose to describe the brown beers of Flanders as 'red', which has lead to no small amount of confusion. Today, the consensus seems to be that the old beers of West-Flanders are 'red-brown' and those of East-Flanders are 'brown', but historically they were all 'brown'.

There definitely remains more research to be done on to fully understand the history of this beer style. Contributions of any kind are most welcome.

See also:

• Part 1 and Part 2 of "A small history of Flemish old brown (and red)" by Roel Mulder.
• MTF thread with thoughts from Roel Mulder, Lars Garshol, and others on the history of Flanders brown beer.
• "Flemish brown, red or red brown? How Michael Jackson invented a beer style out of thin air," by Roel Mulder.

Protection Seeking

In April 2011, a group of brewers within Belgium called HORARB ("Hoge raad voor de authentieke Vlaams Roodbruine bieren", or the "High Council for Authentic Flemish Red-brown Beers") formed and intends to seek to make this style a regionally protected style within the EU (Protected Geographical Indication). This group is made up of four brewers in Belgium: Brewery Rodenbach from Roeselare, brewery Verhaeghe from Vichte, Bavik from Bavikhove and Bockor from Bellegem. The proposed name for this style is "Flemish red-brown beer" .

Production Methods

Dusart et al. (2022) describes Rodenbach as being brewed using a portion of highly kilned Vienna or Crystal malt, along with 20% maize. The maize is cooked in a cereal cooker for gelatinization before being added to the main mash. The wort is boiled for a "prolonged" time period, which results in good protein coagulation and is thought to contribute to the minimal amount of foam in the finished beer. "Old" hops are used to reach no more than 10 IBU. The wort is then fermented in epoxy lined tanks for 5-6 weeks before being transferred to large wooden vat to age (see Microbes and Flavor Compounds below) .

Liefmans Goudenband is brewed with all barley, including a small fraction of torrefied malt, and is then fermented in open copper tanks for one week at 20–24°C. The open-air fermentation exposes the wort to an uncontrolled inoculation of lactic acid bacteria, acetic acid bacteria, and wild yeasts. After this primary fermentation, the beer is transferred to stainless steel tanks to age for at least three months. The stainless steel tanks limits exposure to oxygen, which results in less acetic acid production compared to Rodenbach's beer that is aged in oak casks. The aged beer is then blended with young fresh beer and pasteurized to prevent further attenuation by Brettanomyces .

The sour flavor of both Liefmans and Rodenbach comes from lactic acid and acetic acid. Oak aged Rodenbach contains 2500-5000 mg/L of lactic acid and around 1500 mg/L of acetic acid. Liefmans contains similar levels of lactic acid, but only around 1000 mg/L of acetic acid due to the stainless steel aging process. This results in beer that is perceived as less acidic compared to the oak aged Rodenbach beer . Compared to lambic, the aged red-brown beers have more lactic acid and acetic acid than younger lambic (perhaps due to a higher hop dosage in lambic production), but less than aged bottles of lambic (see Spontaneous Fermentation.

See also:

• "For brewery Rodenbach." Peter Bouckaert. Lambic Digest. April 1996.

Microbes and Flavor Compounds

Initial Study

Interestingly, and perhaps frustratingly, Flanders red and brown ales have had far fewer published studies than Belgian lambic beers. The following information is based off of the Martens et al. study from 1997 (see references).

Introduction

While most beer styles are fermented using a monoculture of Saccharomyces cerevisiae or S. pastorianus, Flanders Red Ales are fermented with a mixed culture fermentation. At one brewery (presumed to be Rodenbach) studied by Martens et al. (1997) and then later by Dusart et al. (2022), two beers were produced using mixed fermentation and blended together. The first "light beer" was 11°P and was less acidic, while the second "heavy beer" was 13°P and aged unblended as an Old Ale. Both beers were inoculated with an acid washed yeast slurry that was harvested from a previous fermentation of the "light beer". The yeast slurry contained about 5% lactic acid bacteria after the acid wash. The fermentation of these beers had three stages :

1. A seven day ethanol fermentation at 21°C dominated by Saccharomyces (also present was lactic acid bacteria which was kept to a minimal population due to the acid washing process). After this seven day fermentation, the yeast is harvested and washed for the next brew .
2. A four to five week lactic acid fermentation at 15–21 °C in epoxy-covered tanks dominated by Lactobacilli .
3. The 11°P "light beer" is then blended with aged Old Ale, pasteurized, and packaged (1/3 young "light beer" to 2/3 Old Ale), while the 13°P "heavy beer" is transferred to large wooden vats (foeders). At Rodenbach, this blended and pasteurized product is the Rodenbach Grand Cru .
4. The "heavy beer", which becomes Old Ale, is then aged for a twenty to twenty-four month period of time. During this time, the beer undergoes a long and slow fermentation that is dominated by Brettanomyces, Lactobacilli, Pediococcus, and acetic acid bacteria (Acetobacter). Most of the aged Old Ale is blended with fresh "light beer", but a small amount is packaged unblended as "Rodenbach Vintage" .

The development of the third stage with Brettanomyces and Pediococcus was similar to the development of these microbes in Lambic fermentation. The "light beer" was never allowed to go through the third phase of fermentation, and was instead chilled to 0°C and then used to blend with previous batches of the "heavy beer" and then pasteurized during packaging for stability .

Primary Fermentation

In the brewery studied by Martens et al., the "light beer" was inoculated with a harvested yeast slurry of multiple strains of S. cerevisiae at a rate of 8x10⁶ CFU/mL, and the "heavy beer" was inoculated with 1x10⁷ CFU/mL. Small numbers of Candida guillermondii and Candida datilla were reportedly in the yeast slurry, but their identification was questioned in the study and they were not found during primary fermentation. One interesting finding was that the S. cerevisiae strains used at this brewery formed sexual spores (ascospore), which is quite unusual for brewing yeasts. The yeast in the "heavy beer" grew slower (3 days) and reached an overall cell count that was lower than the "light beer", which reached maximum cell count in 2 days. Yeast slurries with more lactic acid bacteria are generally used to inoculate the "heavy beer", and this may retard the yeast growth in the "heavy beer". The harvested slurry is always taken from the "light beer", which may be less adapted to the fermentation of the "heavy beer". Also, after 1 week the yeast flocculated and settled out better in the "light beer" than they did in the "heavy beer". Although lactic acid bacteria were in the yeast slurry, their growth started only after 4 days into the primary fermentation. No enterobacteria or acetic acid bacteria were found during this first phase of fermentation .

The lactic acid bacteria found in the yeast slurry consisted of 18 strains of L. delbruekii ssp delbruekii and 12 strains of L. delbruekii ssp bulgaricus. Small amounts of Pediococcus were also identified in the slurry, but were impossible to isolate with enrichment until they were found in the primary fermentation. During primary fermentation, one strain of L. plantarum, two strains of L. brevis, and one strain of Pediococcus parvulus were identified .

Secondary Fermentation

After the 7 days of the primary fermentation, the beer was transferred to a secondary fermenter and remained there for four to five weeks. Both the yeast and bacteria populations saw a decline during the transfer, and then a small and gradual growth in secondary with the final yeast count being 4.3x10⁵ in the "heavy beer" and 6.4x10³ in the "light beer". Lactic acid bacteria grew much faster and became dominate in the "light beer", whereas in the "heavy beer" they grew more slowly and yeast remained the dominate microbe. This was explained by there being more sugars in the "heavy beer", which gave the yeast the advantage. Acetic acid bacteria were still not detected during secondary fermentation . Lactic acid began to be produced as well during secondary fermentation, with about a third of it being L-lactic acid and two thirds of it being D-lactic acid .

During secondary fermentation, L. delbruekii ssp delbruekii strains dominated over the other lactic acid bacteria found. Additional strains of L. plantarum and L. coryneformis, and an additional strain of L. brevis was found in the "heavy beer". Other than the dominating L. delbruekii ssp delbruekii strains, only a few strains of L. brevis were found in the "light beer" . The "light beer" appeared to have a a smaller diversity of microbes.

Tertiary Fermentation

The same study by Martens et al. looked at two casks during the third fermentation. The "heavy beer" was transferred from the secondary fermentation vessel to the casks to age for two years. At the beginning of the third phase of fermentation, Saccharomyces cell counts began to drop while the appearance of Brettanomyces began. After 10 weeks in the casks, Lactobacilli greatly decreased, giving rise to strains of Pediococcus parvulus. After 12 weeks for Cask A and 18 weeks for Cask B, the beer no longer contained Saccharomyces, and Brettanomyces dominated. Specifically, B. lambicus (now classified as a strain of B. bruxellensis ) and B. bruxellensis were the dominate species, but much smaller counts of B. intermedius (now classified as B. anomala) and B. custersianus were also found. Brettanomyces continued to be the primary microorganisms for 36 weeks in Cask A and 50 weeks in Cask B. After this time period, P. parvulus began to dominate. Acetic acid bacteria also began to make an appearance in the casks, being detected at 27 weeks in Cask A and 40 weeks in Cask B. The exact numbers of the acetic acid bacteria were not reported by this study since they mostly grow on the surface of the beer inside the cask, and possibly on the walls of the cask where diffused oxygen could reach them more easily, and samples were not taken from these sections of the casks. The difference in the time periods for the microbial populations was determined to be affected by the casks themselves, which differed in age, size, and possibly different microbe colonization inside them before they were filled . During the third fermentation phase, lactic acid greatly increased from ~600 ppm to ~4500 ppm after 35 weeks, and continued to slowly increase to ~5200 ppm at 60 weeks, at which time L-lactic was only slightly less (~48%) than D-lactic acid . Acetic acid levels reached 1600 ppm by the end of the third phase. The final pH of the "heavy beer" was around 3.2-3.5 .

Comparison to Lambic

Lambic is a similar beer produced in Belgium, but is fermented using spontaneous fermentation. Enterobacteria were not found in the Flanders red brewery that Martens et al. studied since spontaneous fermentation was not used. However, after the enterobacteria and primary Saccharomyces fermentation phases of lambic brewing are complete, the microbial populations of lambic and Flanders red/brown beers are similar during their aging processes. Both beers display a dominance by Brettanomyces and Pediococcus during the aging phases. Flanders Red Ales differ by having a large portion of the acid production performed by Lactobacilli, where as in lambic the acid production is performed by Pediodoccus damnosus. Flemish red-brown beers are also characterized by having P. parvulus instead of P. damnosus (although this may have been misidentified; see Modern Analysis below), however Martens et al. noted that the two species have no clear difference as far as their effects on fermentation go. Martens also noted that Brettanomyces began to disappear from old English Porter when the beer moved from wooden casks to metallic ones. It is thought then that the wooden casks are vital to Brettanomyces in Flemish red-brown beer brewing, perhaps due to the presence of Pediococci, with which Brettanomyces "cooperates" to ferment dextrins in the beer during the aging phase .

Belgian brewers have even married the Flemish red-brown beer and lambic by blending the two beers together. The Flanders "acid beer" is fermented with cherries, and later on lambic is added and the blend is allowed to referment in the bottle, creating something truly special .

Modern Analysis

A more recent study by Snaewaert et al. (see reference ) looked at the microbial and metabolic composition in the finished beer of the same brewery as Martens et al., as well as two other Flemish red-brown beer breweries using "state of the art" DNA sequencing methods. Three samples were analyzed (A, B, and C) from each brewery (1, 2, and 3). As expected, there were both similarities and differences between the three breweries tested, as well as some differences between the individual beers from each brewery. See Microbial Populations below.

In 2022, Dusart et al. analyzed and compared flavor compounds of a bottle of 2015 Rodenbch Vintage, a 2021 bottle of Rodenbach Grand Cru, and a 2021 bottle of Liefmans Goudenband, using solvent-assisted flavor evaporation (SAFE) and static headspace analysis, followed by GC-MS analysis. They also included n-Hexanol extraction of short-chain fatty acids and HPLC analysis of iso-alpha acids . See Rodenbach vs Liefmans Analysis below.

Microbial Populations

Each brewery had their three samples compared, and then also compared to each other. The bacterial populations for Breweries 1 and 3 were similar across all of their own samples, whereas Brewery 2's samples had a larger difference between the three samples of its own beers. The yeast populations were similar between all samples for Brewery 1, whereas Breweries 2 and 3 had a larger difference in yeast populations between their three samples of beer . In summary, Brewery 1 (presumed to be Rodenbach) had similar populations of bacteria and yeast across all samples of their beer, whereas Brewery 3 only had similar populations of bacteria but not yeast across all samples of their beer, and Brewery 2 had the least amount of similarity in yeast and bacteria populations between their beer samples. This indicates that the beers from Brewery 2 were less consistent.

Overall, the samples were mostly dominated by Pediococcus damnosus and Brettanomyces bruxellensis, except for two samples of Brewery 2 that were dominated by Acetobacter, and one sample from Brewery 2 and two samples from Brewery 3 that were dominated by an unidentified yeast. Note that these findings conflicted with the findings of Martens et al. who identified P. parvulus as the dominating Pediococcus species. These two species are closely related, and an explanation of this discrepancy between the two findings was never found. Acetobacter numbers were higher in Brewery 1 and 2, and lower in Brewery 3, and were associated with the high acetic acid amounts found in the beers. Smaller amounts of Acetobacter in Brewery 1 were identified as Acetobacter pasteurianus, and might be the same species in Breweries 2 and 3. Small numbers of Lactobacillus were found in all samples. Weissella and Leuconostoc were found in some samples from Brewery 2, whereas only trace amounts of Wessella were found in one samples from Brewery 3. A significant amount of Pichia yeast were found in two of Brewery 2 samples, and trace amounts in the third sample from that brewery. Only trace amounts of Pichia yeast strains were found in Breweries 1 and 3. Brewery 1 had some amount of Candida yeast in all samples. Brewery 3 had some amount of Candida in one sample, but only trace amounts in the other two samples, and Brewery 2 had only trace amounts of Candida across all three samples. Although detected with DNA sequencing methods, Lactobacillus and Candida along with other yeast could not be isolated and grown under lab conditions .

Only one OTU was assigned to Kregervanrija, Debaryomyces, Priceomyces, Hyphopichia, and Wickerhamomyces yeasts, consisting of 0.24, 0.08, 0.07, 0.03, and less than 0.01% of the DNA sequencing reads, respectively . (This wiki entry needs clarification.) This means that only an extremely small amount of these microbes were present.

Metabolic Composition

Snaewaert et al. also looked at the metabolic composition of finished beers in the three breweries before they were packaged. Glucose was completely gone from the samples, but substantial concentrations of maltose, maltotriose, maltotetraose, maltopentaose, and maltohexaose were still present. This contrasts with the relatively high glucose and fructose found in finished bottled versions of these beers, which indicates that the beers were back-sweetened with young beer or with residual sugar or even possibly some form of sugar at bottling time .

Overall the flavor of these beers was dominated by ethanol, lactic acid, acetic acid, ethyl acetate. Across the samples there was also a presence of isoamyl alcohol (31-150mg/L) and isoamyl acetate (1.99-6 mg/L), and an absence of 2-phenyl ethanol and 2-phenylethyl acetate in both the matured beers and the bottles versions. Small amounts of propionic acid, isobutyric acid, ethyl hexanoate, and ethyl octanoate were found. Higher levels of ethyl acetate were found compared to the Martens et al. study, and no ethyl decanoate was found, which is a typical ester found in gueuze. Just as the microbial populations of Brewery 2 differed from Breweries 1 and 3, so did its overall metabolite content. Higher levels of acetic acid were found in Brewery 2, which was attributed to high levels of Acetobacter populations. Additionally, all three of the samples from Brewery 2 differed from each other as far as metabolic content, which was also attributed to the microbial population differences between each of Brewery 2's samples .

Rodenbach vs Liefmans Analysis

In 2022, Dusart et al. analyzed and compared flavor compounds of a bottle of 2015 Rodenbach Vintage (unblended oak aged Old Ale), a 2021 bottle of Rodenbach Grand Cru (blend of 1/3 young beer and 2/3 oak aged Old Ale), and a 2021 bottle of Liefmans Goudenband (stainless steel aged Old Ale blended with young beer). They reported that iso-alpha acid content was low in all three bottles, as expected. Specifically, the Rodenbach Vintage had no detectable iso-cohumulone and only 0.25 mg/L iso-humulone. The Rodenbach Grand Cru had around 1.2 mg/L each of iso-cohumulone/iso-humulone, and the Liefmans had around half that amount. Interestingly, the Liefmans bottle had around 1.5 mg/L of tetrahydroisohumulones, eluding the use of tetra iso-alpha hop extract, which has been found to increase head retention in sour beers .

The phenols 4-ethylguaiacol (4EG) and 4-ethylphenol (4EP) were found in the range of 54-385 µg/l, with the Rodenbach Vintage (unblended Old Ale) having the highest amounts. These levels were still less than typical lambic/gueuze levels. The 4EG levels in Liefmans was only 54, compared to the 236 µg/l in Rodenbach Grand Cru and 384 µg/l in Rodenbach Vintage. Liefmans had a fairly high level of 4EP (123 µg/l), but it was still below the flavor threshold of 150 µg/l. In addition, Liefmans had high levels of of 4-vinyl precursors, indicating that Brettanomyces is not present during the Liefmans brewing process. The scientists suggested that the detected 4EP came from the small amount of torrefied malt used in the Liefmans brewing process, which has been shown to produce small amounts of 4EP .

Style Guidelines

Note: style guidelines are primarily used to help facilitate beer competitions, or to reflect modern commercial beers as best possible. They are therefore not the ultimate authority on all beer styles and throughout history.

BJCP Guidelines

The BJCP breaks this style into two separate categories; see category 23B. Flanders Red Ale and 23C. Oud Bruin.

Brewers Association Guidelines

Belgian-Style Flanders Oud Bruin or Oud Red Ale are copper to very dark. SRM/EBC color values can be misleading because the red spectrum of color is not accurately assessed using these procedures. Chill haze is acceptable at low serving temperatures. Some versions may be more highly carbonated and, when bottle conditioned, may appear cloudy when served. Roasted malt aromas including a cocoa-like character are acceptable at low levels. Brettanomyces produced aromas may be completely absent or very low. Fruity-ester aroma which is often cherry-like is apparent. Hop aroma is not perceived. Roasted malt flavors including a cocoa-like character are acceptable at low levels. A very low degree of malt sweetness may be present and in balance with the acidity produced by Lactobacillus activity. Hop flavor is not perceived. Hop bitterness is perceived to be very low to medium-low, though acidity and wood aging (if used) may mask higher bitterness unit levels. Overall balance is characterized by slight to strong lactic sourness, and with "Reds" sometimes a balanced degree of acetic acid. Brettanomyces produced flavors may be absent or very low. Fruity-ester flavor which is often cherry-like is apparent. Oak-like or woody characters may be pleasantly integrated into overall palate. Residual wine or distilled spirits flavors associated with used barrels should not be evident. Bottle conditioned versions are often blended old with new before packaging in order to create the brewer’s intended balance of characters. Body is described as a refreshing mouthfeel.

• Original Gravity: (ºPlato) 1.044 - 1.056 (11 - 13.8)
• Apparent Extract/Final Gravity: (ºPlato) 1.008 - 1.016 (2.1 - 4.1)
• Alcohol by Weight (Volume): 3.80% - 5.20% (4.80% - 6.60%)
• Bitterness (IBU): 5 - 18
• Color SRM (EBC): 12 - 25 (24 - 50)

See Also

Additional Articles on MTF Wiki

• Mixed Fermentation
• Blending
• Lambic
• Saccharomyces
• Brettanomyces
• Lactobacillus
• Pediococcus

External Resources

• Rudy Ghequire from Rodenbach on the Sour Hour
• Interview with Rudi Ghequire on Belgian Smaak podcast.
• Designing and Brewing a Flanders Red Ale, by Matt Miller of Sour Beer Blog.
• CRAFT Beer: Quantitation of the Major Components of Commercially Available Sour Beers Using Time-Domain CRAFT Analysis of ¹H NMR Spectra.
• "Hanging out with Eric and Lauren Salazar at the New Belgium Sour Symposium" by Adam Kielich, 4/25/2016. Detailed information about NBB's foeder and blending program.
• "Flanders Red: Style Profile," BYO May/Jun 2014, Jamil Zainasheff.
• "Rosa Merckx (The icon you need to know)," by Brandon Jones, Embrace The Funk blog. An article on the first female Belgian brewmaster and brewmaster at Leifmans.
• "Flemish Red Brown Beers", Presentation by Rudi Ghequire at CBC 2012.
• "Tasting Together: Flanders Red Ale with Master Cicerone Pat Fahey," Cicerone Certification Program YouTube Channel.