Beer/Brewing 101 – The Brewing Process
In this instalment of brewing 101 I am going to go over the entire brewing process. You can see the previous post here. We will go from water, malt, hops and yeast and make some beer. This will, once again, be an overview of each process. Once I get through the broad overviews the plan is to go back and cover the parts in more detail. This may be in specific posts or as part of covering a style.
The first step is to make the wort. The wort is the base of the beer before fermentation. To do this we first take the malted barley and crush it in a mill. We are just cracking open the grains and not pounding them into flour. This allows us access to the starchy sugars in the grain but leaves the husk intact to act as a filter. The grain is then mixed in the mash tun with hot water at a ratio of around 2-3l per kg of grain. A basic single step mash will be held at around 66C for around an hour. More complicated mashes with multiple temperature rests at different temperatures can be done to achieve particular results but are not as common as single infusions. The mash allows enzymes to break up the starches in the grain and convert them into more simple sugars the yeast can consume.
At the end of the mash the liquid, now called wort is transferred to the kettle. A kettle is a large pot/vat that the wort will be boiled in. While emptying the liquid from the mash tun more hot water will be added to rinse the grain and get all available sugars, this process is called sparging.
Once in the kettle the wort is brought to a boil. The boil has two main purposes in brewing. One reason is to sanitise the wort and kill of anything that may infect and spoil the beer. The next reason is where the hops come in. The wort will be boiled for normally 60-90minutes. During the boil hops will be added at different times. Additions of hops in the 45-90 minute are, primarily, to provide bittering. The alpha acids from the hops are dissolved into the solution and this provides the bitterness. Hops added in the time from will add little to aroma or flavour as the oils that come from the hops will be boiled off. Additions of hops in the 0-30 minute range are the flavour and aroma additions. The closer to the end of the boil the more aroma you will get but the less bittering character. This is why there is normally a range of additions across the length of the boil depending on the style.
Once the boil is completed the wort need to be cooled. It needs to be cooled as quickly as possible to avoid reactions that can cause off flavours in the beer. This is not always the case but is the normal process in brewing. A typical way of doing this is to run the hot wort through pipes that are jacketed by another larger pipe. In the outside pipe you run refrigerated water in the opposite direction. This is called a counterflow chiller. There are also plate chillers that work on a similar principle and immersion chillers that involve submerging cool pipes into hot wort. Whilst not the only method of chilling these are the most common.
After or normally during the cooling phase the wort is transferred to the fermenter. At this point the wort may be oxygenated or aerated to assist the yeast. The yeast which can be in a dry powder like or liquid for is now added to the fermenter and the fermenter sealed to prevent wild yeast or bacteria getting in. However, carbon dioxide will need to escape so we need a air lock. Commonly this is a hose from the top of a fermenter into a bucket of sanitised liquid. This can take many forms but the hose and bucket is common.
Now the yeast goes to work eating all the sugar and producing alcohol and C02. This process can take anywhere from three days to weeks depending on how high in alcohol the beer and the style of beer. Typically lagers and high alcohol beers take longer. Fermentation of ales is normally at 18-22C and lagers at 8-12C. For some styles of beer, like IPA, hops can also be added into the fermenter to add extra aroma to the beer, this is called dry hopping. Once fermentation is complete and the yeast have eaten all the sugar the beer may be cold conditioned or lagered. This means keeping the beer at a very low temperature, as close to freezing as possible, for an extended period. This can help drop yeast and other compounds that can cause off flavours out of the beer. Almost all lagers will be, unsurprisingly, lagered but some ales will be also. Beer may be filtered also at this time.
Once there process are complete it will be packaged into kegs, bottles or cans. Most commonly the beer will be force carbonated at this time by taking C02 and forcing it into the beer. However, some brewers like Coopers and Little Creatures will add a little fermentable material and a little extra yeast and allow it to ferment again the bottle/keg. This produces the carbonation naturally but takes a little longer. There are other carbonation methods but these are the most common.
That is how beer is made. This is a basic description that does skip over a lot of detail and uses some language that isn’t technically accurate so as to make it’s point simply. I will go into further detail over the course of this series. If you want something else to read now you should check out “How to Brew” by John Palmer. It’s a great book and a really good starting point to learn about how beer is made.
Please let me know in the comments if you have any questions. I would love to hear what people think and use it to guide the series.
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I'm Here For The Hops » Beer/Brewing 101 – Malt and Mashing posted on July 18, 2010:
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