Brewing process

Welcome to the beginner’s course of beer brewing

We have all the basic ingredients of beer – water, hops, malt and yeast – available to start brewing. The final brewing result depends on the specific procedures, fermentation periods, temperatures etc. We would like to guide you through the basic steps of the brewing process.

At Kasteel Brouwerij Vanhonsebrouck we brew beers of high, spontaneous and mixed fermentation. The difference between the types of fermentation will also be discussed in this beginner’s course.


The brewing process starts already outside the brewery walls with the malting of grain. Malting is a crucial stage in the production of beer. Barley is mainly cultivated to brew beer, but other grains such as wheat, rye or oats can also be turned into malt as the basis for beer. The malting process starts with cleaning and soaking the grain in water to germinate followed by kilning (or drying) the malt at a high temperature. Kasteel Brouwerij Vanhonsebrouck buys its malts from domestic and foreign malt houses carefully selected and strictly inspected.

When choosing malt, we are very critical because the malt is very important for the colour, aroma and flavour. Once arrived at the brewery, the malt must be milled. Therefore, the malt is put into a grinding mill and crushed. Grinding (or coarse milling) the malt is important to easily mash the malt in the next brewing step.


Mashing consists of mixing the coarsely crushed malt and water in a mash tun. Both the quality and the flavour of the water must be optimal. That’s why the water composition is extremely important for brewing our beers.

During the mashing process we mix the water and the malt. The result is more or less a pasty mixture of spent grains. During this phase, the starch from the malt is converted into fermentable sugars at various temperature levels. Temperature plays an important role in activating natural enzymes in the malt to convert the starch into sugars. Different temperature levels affect the release of fermentable sugars. In this way, the malt also influences the fullness and the foamy head of the beer.


After mashing, a sugary liquid with yeast residue remains. In the next step of the brewing process, we separate the remaining yeast residue from the spent grains. We keep it temporarily in silos. After they are collected and distributed among dairy farmers. The legal distribution of spent grains that are generally used as cattle fodder is possible thanks to the FCA certificate.

After filtering, the remaining yeast residue is separated and wort remains. Wort is the filtered malt extract that will become beer.


The wort is ready and can now boil for at least 1 hour. Meanwhile, we also add hops and spices. We only use hop cones of the female hop plant. Boiling largely dissolves the hops into the wort and gives it its bitter aromas and flavours. Therefore, the brewer usually starts with bitter hops that contains bitter substances to give the beer its typical bitterness. Aroma hops are added towards the end of the boiling process. The hops for our beers come from everywhere. For example, our Kasteel range contains sweet Golding hops, a British variety of hops. For Brigand we use Saaz-hops from the Czech Republic.

After it has been boiled, the wort has to cool off. The high fermentation beers must cool off to a temperature between 15-25 °C. For our spontaneous fermentation beers, we pump the boiling wort into an open cooling tank. This way it can be infected with the surrounding microflora that causes spontaneous fermentation.


During the fermentation process, the fermentable sugars are converted into alcohol and carbon dioxide. At a high temperature, fermentation takes 1 to 2 weeks. During the conversion process many aroma components are released. We can only talk about beer after all the sugars have been converted. We use three types of fermentation:

  1. High Fermentation The fermentation takes place at a high temperature between 15 and 25 degrees. This type of fermentation applies to most specialty beers of our range.
  2. Spontaneousfermentation The wort is not cooled after boiling and is directly pumped into an open cooling tank. This way it can be infected with the surrounding microflora. This type of fermentation applies to our lambic and gueuze beers.
  3. Mixedfermentation After the main fermentation, the wort is pumped into oak barrels. A lactic acid fermentation takes place. This type of fermentation applies to all Bacchus beers.


Once the main fermentation is finished, the beer can rest and age in lager tanks. While it is ageing or lagering, the yeast sinks to the bottom, the remaining sugars are converted into specific aromas and less pleasant flavour components disappear. Lagering creates balance in the beer so that the flavour will remain stable. When necessary, the brewer adds extra elements.

For the preparation of our fruit beer, for example, we add fruits. During the 6 month lagering period the flesh of the fruit completely dissolves and the flavour of the fruit is absorbed into the beer. For Kasteel Hoppy the brewer applies the dry hopping technique. He adds extra hops during the lagering process which gives a subtle bitterness.


Filtering is required for a second time during the brewing process. By filtering the beer we remove the remaining yeast residue and cloudiness from the beer. The excess yeast is kept in silos until they are collected by an authorized distributor. Yeast contains a lot of vitamins for pigs and can therefore be used as pig feed. Kasteel Brouwerij Vanhonsebrouck is legally allowed to distribute the yeast thanks to the FCA certificate.

This phase of the brewing process is very important for our gueuze and fruits beers. This is the moment when the brewer prepares a blend of old and young lambic before bottling.


It’s time to bottle the beer. Kasteel Brouwerij Vanhonsebrouck has its own bottling plant, where the beers are bottled under the strictest hygienic conditions. The beer can be bottled in barrels, bottles or cans. The bottling usually takes place in our brewery on Tuesday and Wednesday, and if necessary also on Thursday morning.

Our brewery has three bottled second fermentation beers, namely Filou, Kasteel Tripel and Brigand. Before bottling, the brewer adds sugar and active yeast. Then they are stored for several weeks in a warm room of maximum 23°C. This is the ideal temperature to start the re-fermentation in the bottles, which gives the beers their characteristic flavour and aroma.


The brewing process is completed and now it is of course time to taste the beer! Does the beer have enough bitterness? Do the fruit aromas stand out sufficiently? These questions can only be answered at the end of the brewing process. Once approved, the barrels, bottles and cans of beer can be sold to the consumer.

You too – beer lover par excellence – can now judge and enjoy the beer. We hope that the foamy head is a treat for your eyes, that the bitter aromas can titillate your nose and that the subtle flavours unique to our brewery can caress your tongue. Only when you are satisfied, we are too!