Production methods

After the grain has sprouted and been dried out, the malt which is produced in this way is first cooked with water and hops to make the wort. This is the point at which the fermentation phase occurs. For the wort to ferment, yeasts must be added to it that will turn the sugar in the wort into alcohol and carbon dioxide.

And it is here that Belgium really stands out, as the only country in the world to brew beer using all four production techniques.


Bottom fermentation

Bottom fermentation requires the addition to the wort of ‘lager yeasts’. During fermentation, the yeast migrates to the bottom of the barrel.

The fermentation process takes 7 to 10 days at a temperature of between 4 and 12 degrees.

Lager yeasts produces less alcohol and result in beers with less complex flavours than those obtained by top fermentation. They taste of hops and malt, tend to be less fruity and have a lower alcohol content than other beers and are consumed chilled, usually at between 4 and 7 degrees.


This is the method used for the traditional pils or pilsener. Jupiler, Maes and Stella Artois are known all over the world. More local products such as Vedett extra blond (Duvel Moortgat), Manneken Pils (Brasserie Lefebvre) or Silly Pils (Brasserie de Silly) are examples of traditional pilsener lagers (or at any rate ones of a less industrial character than those mentioned earlier), and are surprisingly tasty and refreshing.


Top fermentation

Top fermentation requires the addition into the wort of ‘ale yeasts’. Fermentation takes 3 to 8 days at a high temperature of 15 to 25 degrees.

When the yeast has used up the glucose, it rises back up to the surface of the beer, where it floats (hence the name).

Top fermentation is the most widespread brewing method in Belgium. It is associated with complex flavours. The beers produced in this way usually have less carbon dioxide than the bottom-fermented beers and are consumed at a higher temperature, usually between 6 and 12 degrees.


Over 90% of Belgian beers are top-fermented. You only have to try a Trappist beer such as Orval or Rochefort or an abbey beer such as Floreffe, Val Dieu or Grimbergen to appreciate the aromatic richness produced by this fermentation method.


Spontaneous fermentation

Unlike top and bottom fermentation, spontaneous fermentation does not involve adding yeast to the wort, which is instead exposed to air-borne wild yeasts. This was how beer used to be produced before the discovery of the properties of yeasts in the Middle Ages.

This technique is used by the brewers of the Senne valley and Pajottenland region near Brussels, and gives the beer a very characteristic sour taste. The beers produced using this technique are known as lambics.


If you want to try the products of spontaneous fermentation, there are several types: lambic (3Fonteinen Doesjel); gueuze (a blend of old and young lambic, producing a sparkling, acidic ‘champagne beer’: 3Fonteinen Oude Geuze, Girardin Gueuze); kriek (a blend of cherries and lambic: Boon Kriek Mariage Parfait, Cantillon Kriek); and faro (a blend of brown sugar and lambic: Faro Lindemans). 


Mixed fermentation

Mixed-fermentation beers undergo initial top fermentation and are then exposed to wild yeasts for a second, spontaneous fermentation, usually in oak barrels.

Keeping the beer in these oak barrels enables the fermentation process to be completed, but also contributes a considerable amount of extra flavour. After up to three years of maturing, the sweetness is transformed into a sourer, slightly more alcoholic beer. Old and young beers are then blended to combine sweetness and sharpness.


The best-known mixed fermentation beer is Rodenbach from the Oudenaarde region; however, you should also try other delicious examples such as Bacchus, Bourgogne des Flandres and Liefmans Goudenband.