Storage or secondary fermentation:

Biochemical and biological processes take place during the 4 main stages of the brewing process.

Stage 4: Storage or secondary fermentation:

The beer is kept in a storage vat for around 24 hours at a temperature near to 0°C.

The purposes of this stage are as follows:

To refine the flavour

To allow the beer to clarify naturally

The beer is then packed in different formats, either 33 or 75 cl. bottles, 5 litre mini kegs, or 20 and 30 litre kegs. To encourage fermentation to start again after bottling, the bottles are placed in a warm room for 24 hours. During this stage the beer becomes naturally saturated in CO2.

The purposes of this stage are as follows:

• to refine the taste and flavour of the beer (the "green beer" taste, mainly created by sulphur compounds and diketones, lessens while the flavour from the higher alcohols and carbonyl compounds increases; unpleasant compounds like diacetyl and mercaptans are eliminated during storage)

• to allow suspended matter, yeast, colloids and amorphous substances, to settle

• to allow maturation process to take place in the absence of air

Afterwards, the beer is bottled (33cl or 75 cl) or transferred to 30 litre kegs.

Once they have been bottled and keg filled, the beers are placed in a warm room (24°C) for around 24 hours. Triple fermentation of the beers occurs at this moment. The beers become saturated in CO2.