Malt grains are milled in a flourmill, in order to extract the flour they contain, and are then transferred to the mash tun, where they will be mixed with hot water.
Water and malt are stirred for one hour and a half at specific temperatures ranging from 55° to 72°C, in order to extract the sugar contained in the malt as starch. The mixture obtained is called “mash”.
After going through the lautering tun, the mash is separated into wort (extracted sugary liquid) and spent grain (grain husk). The spent grain is then washed with hot water at 80°C in order to extract as much sugar as possible. The spent grain will serve as cattle feed; the wort will be boiled in order to brew the beer.
The wort is boiled at 100°C for one hour and a half. The goal is to sterilize the wort, to adjust its sugar level, to clarify it, and to add flavours with hops and various flavourings. This step in the brewing process clarifies the wort through the formation of a hot break (aggregation of proteins denatured by heat).
Before it is transferred to the fermentation tanks, the wort is filtered to remove the hops and flavourings, then it is cooled down from 95° to 25°C with a plate cooler. During this step, the wort is oxygenated with the use of a spark plug, which facilitates the start of fermentation. Seeding is then carried out using yeast.
For 5 days, the yeast added to the wort at the beginning of fermentation (oxygenated beforehand) will feed on the sugar present in the wort and transform this sugar into alcohol and carbonic gas.
At the end of fermentation, the beer is cooled down to a temperature close to 0°C, which results in the yeast flocculating and floating down to the bottom of the tanks. The beer can then start maturing.
During its maturation at low temperature (2°C), the young beer will ripen, become gas-saturated and clarify. This step usually takes 10 days.
Once the beer has been matured, it is conditioned into kegs or bottles. For bottle conditioning, sugar and fresh yeast need to be added to the beer for an additional 10-day fermentation in a warm room, which will give the beer its fizz.
