The magic of brewing

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The magic of brewing

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.

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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.

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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.

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Wort Whirlpool

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

Water – a complex liquid

In previous posts I’ve talked about the basic ingredients and about yeast and the fermentation itself. What I’ve barely mentioned and what is basically the foundation of beer is water.

water_homebrewingIt might not seem that important to people who are unfamiliar with industrial processes. “Just take some tap water and throw it in with the other ingredients” you might say. Unfortunately it’s not that easy. Water as we know it, bottled or from the tap, contains a lot of “contaminants” for usage in industrial processes. Beer contains 90% water and to make 1 litre of beer you need approximately 3 litres of water. There are two ways of retrieving water for brewing purposes. Surface water from lakes, rivers,…; and groundwater, which is pumped up from below the surface. Old breweries were often built on top or near a place where they pumped the water from the ground for direct usage and minimum transport costs. Nowadays this isn’t necessary any more as water is corrected to a constant quality and to the norms of the brewery.

The choice of water affects the beer in three different ways: It affects the pH which affects the flavour of the beer as it activates different types of taste buds on the tongue, the water’s sulfate to chloride ratio ‘seasons’ the beer and chlorine and other contaminants can cause unwanted, bad tasting flavours.

The main ‘evildoers’ in water are ions (iron, calcium, sulphate,…). If interested you can click here to find out about the effect of every ion on the beer’s taste as it’s too elaborate to explain it all in this dense blog post. There are two types water, soft and hard; both can be used to brew beer. The unit of water hardness is ‘French  Degrees’ or °FD and the difference between the two is the quantity of Calcium and Magnesium ions.

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The used water goes through a series of processes before it can be used in the final product. It needs to be de-ironed, decarbonised, demineralised, sterilised and degassed. There are different methods for each step depending on the preferences of the brewer, available space (for the necessary machinery), cost of the investment, danger,…

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Oxidization in beer

The most important process is degassing. This is the process where oxygen is eliminated from the solution. The amount of oxygen in water is often mentioned as dissolved oxygen (DO) in mg/l or ppm (parts per million). For beer the maximum amount is 0,02 mg/l. The reason for this is that oxygen oxidises beer. Oxidization is the cause of stale flavours as molecules in the beer undergo a chemical reaction with oxygen.

There are two ways of degassing water. The first method is vacuum degassing where the beer is brought into an environment with low pressure so that oxygen spontaneously leaves the beer. Another method is pressure degassing where the beer is placed in a keg with pressurized carbon dioxide or nitrogen so that the oxygen is pushed away by the pressurized gasses.

Now you might wonder, “if beer contains 90% water then can’t I just give up on drinking boring water and drink beer as a substitute”? How wonderful (and perhaps a bit alcoholic) that might sound you wouldn’t last very long. Alcohol has a diuretic effect causing the net balance of the water intake and the alcohol’s diuretic effect to be negative meaning you’d dehydrate.
We’ve all suffered from hangovers. The reason why you have feel so bad after a night of drinking is because of dehydration. Thus, depending on the alcohol percentage, you’d only last for a couple of days. Sorry to break it to you but at least you now know it’s not worth the try.

Now go grab yourself a glass of beer (or water) and I’ll you next time, cheers!
~Blancke The Brewer

Fermentation & real ales

Beer  is a fermentation product. Yeast turns sugars into alcohol and carbon dioxide while the other components give flavour to the beer. The most common type of yeast is the Saccharomyces cerevisiae and is used all sorts of processes from baking to brewing and other things. It’s one of the most intensively studied micro-organisms. Researchers have mapped its entire genome and thus it can be genetically modified to the specific requirements of any process.

There are three  main types of fermentation being top-, bottom- and spontaneous fermentation. Lagers and other common types of beers use bottom fermentation where the yeast sinks to the bottom of the fermenter and takes place at a low temperature (7-13°C).
Spontaneous fermentation is the process where mother nature takes over. The beer is inoculated with a wild-type yeast rather than a specifically cultivated type of yeast. The final product is thus not determined by the brewer. The flavours are sometimes buffered in case it gets too acidic. A famous example of this type of beer is Lambic.
Ales and some stouts will use top fermentation. Top fermentation lets the yeast form a thick foamy head on top of the fermenter and is carried out at higher temperatures. This makes the process shorter. Top fermentation is often carried out in open vessels. This causes a greater risk for infection but with the right safety measures this shouldn’t cause a problem.

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The biggest difference between the these types of fermentations is whether the beer is ‘alive’ or not. Lagers and other beers that are brewery-conditioned are chilled after the fermentation process, have their yeast removed and are pasteurised to make it sterile. They’re also force-carbonated while being tapped or bottled.

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Secondary fermentation in bottle

Ales don’t go through this process which is why they’re referred to as ‘alive’ or ‘real ales’ as they contain living organisms in their final product. The yeast in the final product gives the beer its finishing touch and maturity as it ferments the leftover sugars and carbonates the bottled product, this is called secondary fermentation. This causes the beer to have a shorter shelf-life than other types of beer and need to be taken care of during storage at home or in pubs.

When I spent my days in Ireland I visited the Smithwick’s ale brewery in Kilkenny. I got to sample a lovely pint of Smithwick’s red-ale and in my opinion it’s one of the best classic ales. So for anyone wondering what an ale tastes like I advise you to get your hands on a freshly tapped ruby-coloured pint of naturally fermented and carbonated goodness.

Sláinte!
~ Blanckey The Brewer