Belgian Beers Vs. Sour Beers: What's The Difference?

Belgian beers and sour beers are not mutually exclusive categories. Sour beers are made by allowing wild yeast strains or bacteria to enter the brew, and Belgian brewers often allow this to happen through the barrels or during the cooling process. Two traditional Belgian sour beer styles are Lambic and Flemish sours. Lambics are spontaneously fermented in open air in the Pajottenland region around Brussels, Belgium, and Flemish sours are made in the Flanders region of Belgium. However, not all Belgian beers are sour, and sour beers are also made in other countries, including Germany and the United States.

Belgian sour beers are often aged in oak barrels

Oak is the wood of choice for barrel-aged beers, though other types of wood such as chestnut, ash, poplar, and cedar are also used. The oak barrels contribute to the unique flavour profile of the beer. The three most common types of oak used by brewers are American, French, and Hungarian oak, each imparting its own distinct balance of flavours and complexity.

The flavours derived from oak barrels depend on various factors, including the oak species, the growing area, and the treatment of the wood. New oak barrels, for instance, impart flavours of wood, vanilla, dill, spice, and toastiness. On the other hand, used barrels from wine regions can introduce microbes that contribute to spontaneous fermentation and the sour character of the beer.

Aging in oak barrels also allows brewers to masterfully blend batches from different barrels and years to achieve their desired flavour profile. This blending technique is commonly used in Flanders red ales, where mature beer is blended with younger beer to adjust the taste and consistency.

The Rodenbach Brewery in Roeselare, Belgium, is a well-known producer of Flemish Red-style ales. They age their beer in oak barrels inoculated with Lactobacillus and other bacteria to achieve the desired acidity and flavour. The use of oak barrels and blending techniques are crucial steps in the creation of Belgian sour beers, contributing to their unique character and complexity.

Belgian beers are made in sterile environments with specific yeast strains

Belgian beers, including the famous sours, are made in sterile environments with specific yeast strains. This is in contrast to sour beers, which are made by intentionally allowing wild yeast strains or bacteria into the brew. Belgian brewers have a long history of expertise in brewing, with knowledge of yeast and its role in fermentation dating back to the mid-1800s. By creating a sanitary environment, Belgian brewers can carefully control the type and amount of yeast used, resulting in a diverse range of beers with distinct flavours and characteristics.

Belgian beers are known for their variety, ranging from sweet and strong Belgian Blond Ales, Dubbels, and Tripels to the unique and complex Belgian Sour Beers. This diversity is a result of the country's rich brewing history and the skilled use of specific yeast strains. Belgian brewers have mastered the art of yeast selection and fermentation control, allowing them to produce beers with consistent quality and flavour profiles.

Belgian Sour Beers, on the other hand, are created by allowing wild yeast strains, such as Brettanomyces, to enter the brewing process. This wild yeast imparts earthy, funky, and fruity notes to the beer. However, the Belgian brewing tradition extends beyond sours, and their beers are crafted with precision and a deep understanding of yeast and fermentation.

The sterile environment in Belgian brewing ensures that the specific yeast strains selected by the brewer are the primary contributors to the fermentation process. This controlled approach allows for consistency in the brewing process, enabling brewers to create beers with predictable characteristics. By excluding wild yeast and bacteria, Belgian brewers can produce a wide range of beers, from robust and sweet to delicately balanced, each with its own unique flavour profile.

Belgian brewers take pride in their craft, and their attention to detail, including the use of specific yeast strains in sterile environments, has contributed to the country's renowned beer culture. While Belgian Sour Beers may deviate from this traditional approach by embracing wild yeast, the majority of Belgian beers are meticulously crafted in carefully controlled conditions. This combination of traditional techniques and modern understanding of yeast management has elevated Belgian beers to a globally recognised standard.

Sour beers are made with wild yeast strains

Historically, the starter used from one batch to another usually contained some wild yeast and bacteria. Sours are made by intentionally allowing wild yeast strains or bacteria into the brew, usually through the barrels or during the cooling of the wort in a coolship open to the outside air.

The most common microbes used to intentionally sour beer are the bacteria Lactobacillus and Pediococcus. Lactobacillus is the primary bacteria responsible for most sour beers. It is also the bacteria found in yoghurt and sour cream. It does the same thing yeast does in terms of attracting sugar, but instead of alcohol, it creates lactic acid, which has that sour flavour and aroma. Expect a clean and crisp sour flavour from Lactobacillus that will balance well with other flavours and aromas that complement it.

Pediococcus is also a bacteria that creates lactic acid in beer during fermentation, but it also creates acidification, which can create a buttery-popcorn aftertaste. The best trick is to make sure you combine Pediococcus with Brettanomyces to balance the two effects out.

Brettanomyces is the most commonly used yeast for sour beer. While Brettanomyces is not responsible for the souring of beer, it tends to enhance any sourness and smooth it out properly, so any aromas and flavours that naturally sour the beer will be highlighted by it. Brettanomyces is still considered a wild, unpredictable yeast, and it takes much longer to ferment than Saccharomyces Cerevisiae, so it is worth playing with measurements and lengths of time if you allow Brettanomyces in to play with your fermentation process.

Belgian sour beers include Flanders Red Ale and lambic/gueuze styles

Flanders Red Ale is a sour ale style brewed in West Flanders, Belgium. It is fermented with organisms other than Saccharomyces cerevisiae, especially Lactobacillus, which produces lactic acid and gives the beer its characteristic sour flavour. Flanders Red Ales are often aged for long periods, a year or more, in oak barrels, to impart this lactic acid character. Red malt is used to give the beer its distinctive red colour, and the matured beer is frequently blended with a younger batch before bottling to balance and round out its character.

Flanders Red Ales have a strong fruit flavour, with plum, prune, raisin and raspberry being the most common, followed by orange and a hint of spice. The sour or acidic taste can vary from moderate to strong, and they are often described as the most wine-like of beers. Notable examples include Duchesse de Bourgogne, Rodenbach and VanderGhinste Roodbruin.

Lambics, on the other hand, are spontaneously fermented beers made in the Pajottenland region around Brussels, Belgium. The wort is left to cool overnight in a koelschip, where it is exposed to the open air, before being placed into barrels to ferment and mature. Lambics are often used as base beers to create other styles, such as gueuze. Gueuze is made by blending older and younger lambics together, and the blended beer undergoes a secondary fermentation in the bottle, resulting in a champagne-like effervescence with a mild oak aroma, fruity esters, and balanced acidity.

Lambics are characterised by a citrus and phenolic aroma, while Flanders Red Ales are known for their solvent-like aroma, sourness complexity, full body, graininess, astringency, and bitterness.

Sour beers are made by allowing wild yeast strains into the brew

Sour beers are made by allowing wild yeast strains or bacteria into the brew. This is usually done through the barrels or during the cooling of the wort in a coolship open to the outside air. The most common microbes used to intentionally create sour beer are the bacteria Lactobacillus and Pediococcus, while the fungus Brettanomyces can also add some acidity.

Lactobacillus and Pediococcus are the two main acidifying bacteria used to sour beer. Lactobacillus is more favourable as it contributes a clean acidity, whereas Pediococcus can offer a more complex acidity but comes with the risk of off-flavours.

The process of making sour beers is risky and specialised. It can take months to ferment and potentially years to mature. However, modern methods have reduced this time, with some sour beers now being created within a typical timeframe for ales, which is usually several days.

Sour beers are made by intentionally allowing wild yeast strains or bacteria into the brew. This is typically done through the barrels or during the cooling of the wort in a coolship open to the outside air. This process allows wild yeast and bacteria from the environment to give the beer a better sour flavour.

The wild organisms used to make sour beer can bring a wide range of flavours, from intensely sour to light and fruity to downright funky. More well-known types of beer use specific yeast strains in a sterile environment to maintain tight control over the brewing process and produce more familiar flavours.

Sour beers are often labelled as "sour/wild". The sour flavour comes from lactobacillus, while the wild flavour comes from Brettanomyces, or Brett.

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