How To Brew Lambic Beer: Belgium’s Spontaneous Wild Yeasts and Wonderful Beers

Lambic beer history is very elusive. Brewed in the Pajottenland region of Belgium southwest of Brussels and in Brussels as well since the 13th century.

Lambics are fermented by exposing the wort to wild yeast and bacteria that is native to the region in which it is brewed, as is the case in Belgium it is the Zenne valley.

This is unique to sour brewing as it is customary for some sour beers to be pitched with a “carefully cultivated strain.” This leaves the beer with its very specific flavor, dryness, vinous, and tart aftertaste.

Etymology of Lambic

Interesting note for those interested in words. The name lambic was first spelled as “allambique” in 1794. The initial ‘a’ was dropped and in 1811 it was called “lambicq.” Also, it was called ‘alambic‘ around 1829.

A less likely origin derived from the word “allambique” as it was derived from Lembeek, a municipality near Halle, Belgium. 

The Brewing Process of a Lambic

Lambic usually consist of a grist of typically 60-70% barley and 30-40% unmalted wheat. The wort is cooled overnight in a coolship, which is a shallow, flat metal pan, usually copper or stainless steel.

This wort is exposed to open air so some 120+ different types of microorganisms may inoculate the wort. The nighttime cooling process requires the temperature to be between 18°F (-8°C)  and 46°F (8°C).  

Although the cooling method of open air exposure is a critical component to this style, as is the wooden fermenting vessel. Over eighty microorganisms have been identified in lambic beer, with the most important being Saccaromyces cerevisiae, Saccaromyces pasroianus and Brettanomyces bruxellensis.

The air temperature during the months of October and May in Belgium is most ideal as most summer months are too warm and will result in spoiled beer. 

Style Profile for Lambic

Appearance

Color of a Lambic ranges from pale yellow to deep golden. Age will darken the beer. Clarity is hazy to good.

Yonder versions are usually hazy, while older ones are clear. White colored head with poor retention.   

Aroma

A sour aroma is often dominant in younger examples of this beer. As the beer ages, the sourness subsides and blends nicely with aromas of barnyard, earthy, hay, horse blanket.

A mild citrus like aroma is favorable. Older versions may also contain an apple or honey-like aroma. No hop aroma should be present. 

Flavor

Noticeable lactic sour are present with younger versions of this beer. Aged versions tend to be more balanced and bring out the malt, whear, barnyard characteristics.

Fruity flavors tend to be noticable with younger versions and apple, rhubarb, or honey tend to be noticeable with aged versions. Sometimes citrus character is present, especially grapefruit.

The malt and wheat character is low with some bready-grainy notes. Hop bitterness if low to none. The sourness provides the balance in this case. Typically a dry finish. 

Mouthfeel

Light to medium-light body. Lambics dries with age. Medium to high tart, puckering quality without being astringent.

Traditionally, this beer is completely uncarbonated, but bottled versions can develop carbonation with age. 

Tips for Brewing your own Lambic

Grain

The grist for a Lambic is usually 30-40% of unmalted wheat and the rest consists of Pilsner malt.

Hops

As for hops, the IBUs should be under 10. Since hops are antibacterial, they will impede the bacteria needed for this style.

Traditionally, these hops are old, not fresh, low alpha acid, and European. Stay away from high alpha acid hops and citrusy American hops. 

Yeast

Traditionally, this beer is spontaneously fermented with naturally occurring yeast and bacteria found in oak barrels. The oak barrels are usually more neutral and therefore do not give off much oak character in the finished beer.

A mix of Saccaromyces, Pedicoccus, Brettanomyces, Lactobacillus are all common to use when trying to recreate the effects of obtaining wild yeast in Brussels and the surrounding countryside of the Senne River Valley.

Wyeast, White Labs, Imperial Yeast, and Bootleg Biology all have yeast mixtures that contain a mix of Saccharomyces yeast and the Pedicoccus, Brettanomyces and Lactobacillus. 

Lambic By the Numbers

• Color Range: 3 – 7 SRM
• Original Gravity: 1.040 – 1.054 OG
• Final Gravity: 1.001 – 1.010 FG
• IBU Range: 0 – 10
• ABV Range: 5.0 – 6.5%

Lambic Recipe

Grain LME

• 53%        4 lbs.       Bavarian Wheat Liquid Extract 
• 40%        3 lbs.       Pilsner Liquid Extract
•   7%        .5 lb.        Maltodextrin 

Hops

• 1.00 oz         Aged Saaz – Boil – 30 min

Yeast

• 1.0 pkg   German Ale  Wyeast #1007
• 1.0 pkg   Brettanomyces Lambucus Wyeast #5526

Directions:

1. Mash at 152°F (66°C) for 60 mins
2. Boil for 60 mins 

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Frequently Asked Questions

What is Lambic Beer?

Lambic beer is a type of Belgian beer that is known for its unique fermentation process which involves spontaneous fermentation with wild yeasts and bacteria native to the Senne valley, near Brussels.

This results in a distinctively sour and often fruity flavor profile that sets Lambic beers apart from other beer varieties.

The brewing process is traditional and the recipe often includes aged hops which contribute a mild bitterness and act as preservatives, without overpowering the sourness of the beer.

How is Lambic Beer Made?

The process of making Lambic beer is distinctive and steeped in tradition. It begins with a mash of malted barley and unmalted wheat. After the mash, it’s traditionally boiled with aged hops.

The wort is then cooled in a large, shallow vessel called a coolship, allowing it to come into contact with the wild yeasts and bacteria in the air.

This spontaneous fermentation process can take several months to a year or more. The beer is often then blended with younger or older Lambics to create a more complex flavor profile, or it can be further fermented with fruits to create fruit Lambics.

What Does Lambic Beer Taste Like?

The taste of Lambic beer is notably sour, often with a dry, cider-like quality. The wild fermentation process introduces a complex array of flavors and aromas, which can include earthy, funky, or barnyard notes alongside the tartness.

The use of aged hops provides a mild bitterness which is balanced by the sourness. Fruit Lambics, where fruits are added for a secondary fermentation, have additional sweet and fruity notes overlaying the characteristic sourness of the Lambic beer.

How Long Does Lambic Beer Last?

Lambic beers are known for their longevity. Thanks to their high acidity and the presence of alcohol, they can be stored for many years, often improving with age.

While the exact shelf-life can vary, it’s not uncommon for Lambic beers to be aged for several years, with some enthusiasts aging them for decades. It’s advisable to store Lambic beers in a cool, dark place to maintain their quality over time.

What is the Alcohol Content of Lambic Beer?

The alcohol content of Lambic beer can vary, but typically ranges from 5% to 8% ABV (Alcohol By Volume).

The exact alcohol content can be influenced by several factors including the specific recipe used, the fermentation process, and whether the Lambic is blended with other beers or fermented with fruits.

The traditional brewing process and the long fermentation period contribute to the development of alcohol content in Lambic beers.