Up until now I’ve talked about the ingredients, the art and beauty of beer, the fermentation,… but what about the actual process? You have the ingredients, now how do you turn them into a delicious pint of carbonated alcohol? It all starts with the wort production in the brewing halls.
The first step is milling the brewing grain. This can either be done with a roller mill or with a hammer mill. In the first method the grain is being squished between two rollers separating the inner seed and the husk. It is important that the husk is not too damaged as it is used in further steps. The second method is a hammer mill which is exactly what it sounds like. The grains enter a cylindrical container where hammers rotate at a high velocity, pulverising the seeds. The most used method is using multiple sets of rollers.
Breweries will often soak their grains first for approximately 30 minutes at 30-50°C. This allows for a more compact stacking, eliminates most of the air in between the grains and makes the husks more elastic. The milled grains and their husk are called grist.
The second step is mashing which is the actual creation of the wort. The grist is transported to a large vessel called the mash tun, water is added and heated. This is where the magic happens. The barley contains enzymes that need to be activated. Each of those enzymes has a specific temperature optimum. For those who don’t know what an enzyme is, it’s basically a protein that allows certain biological reactions to be conducted at ‘much easier to achieve’ conditions. The reaction not only goes much faster but the temperature at which the reactions goes through is significantly lowered as well. I’m not going into detail what every enzyme does, but on the graph below you can see the temperature at which each enzyme is activated. Each temperature level is held for approximately 30-40 minutes so that each enzyme has the time to do its work. At the end of the process the temperature is driven up to 78°C which inhibits all the enzymes causing them to lose their function.
The third step is a filtration step or ‘lautering’. The mash is moved into a container with a false-bottom. The whole package of grains, husk and mash-liquid is left to settle for a little while causing the husks and grains to settle at the bottom. When the false-bottom is opened the liquid runs through and the husk/grain package functions as a filter. The liquid that runs through is pumped back to the top. This filtering process is repeated for half an hour until the ‘filter’ is completely solid due to the pressure. The obtained liquid is called the primary wort. Afterwards the filter is cleaned with hot water to retrieve the last bits of the wort stuck in the filter which is called the secondary wort.
As a final step the wort is boiled for two hours; stabilising the liquid and sterilises it at the same time. At this stage the hops and extra sugars are added and the acidity is adjusted. If necessary, Zinc is also added as it is a necessity for a good fermentation and foam stability in the final product.
When the boiling process has ended the wort is sent to a “whirlpool” where it is cleared of all leftover solids. The wort is immediately cooled as it reduces the chance of oxidization which produces unwanted flavours.
Afterwards it is sent to a fermenter as I mentioned in this post and the fermentation process can start. After all this work you only have to wait a few more weeks and you’ll be able to sample your own craft beer.
Thinking about this whole process sure made me thirsty, I’m off to enjoy an ice cold beer! Cheers!
~ Blanckey The Brewer