Step 1. Malting
Grains, usually barley but sometimes oat and wheat, are the main ingredients in the beer brewing process. Once these grains are collected, they’re heated, dried, and cracked to isolate the enzymes found in beer.
Step 2. Milling
At the brewery, the malt is passed through a mill. It’s key to crush the malt to the correct size, as this affects the taste of the final product; too much of a fine grind can result in the grain forming into a flour-like powder which creates a stuck mash, too coarse a grind, and the brewer is left with incomplete extraction of starches.
Step 3. The Mashing
Next, the crushed malt is mixed with hot water, which typically ranges from 62-70 °C. This is a steeping process that creates an oatmeal-like substance known as the mash.
The water hydrates the malt, activates the enzymes, and converts the grain starches into fermentable sugars – a future food source for the yeast. This sugary liquid, called ‘the wort’, becomes the body of the beer.
Step 4. Lautering
Before brewing, the wort must first be separated from the spent grains as efficiently as possible.
The first step is called mashout, where the temperature of the mash is raised to 77°C to halt enzymatic reactions and preserve the sugar profile of the wort.
Secondly, loose grain particles are filtered out by flowing the wort out of the bottom of the lauter ton and recirculating it back through the grain bed, resulting in a clearer wort.
After recirculation, the wort is transferred to the boil kettle. Finally, the spent grain in the lauter ton is rinsed, or sparged, with hot water to pull as much of the remaining sugars out as possible.
Step 5. Boiling
The beer is cooked by adding hops (and other flavours) in a large container known as a “copper” or “brew kettle”.
The boiling stage involves reactions that are chemically triggered, which release the hops’ flavours and aromas. Boiling also allows grain proteins to bind with tannins and precipitate out, which reduces the protein haze and flavour in the final product.
Step 6. Fermentation
The fermentation process occurs in conditioning tanks of a variety of sizes, ranging from massive cylinder vessels to open stone vessels to wooden vats. First, the wort must be cooled to a specific temperature, typically between 15-20 °C, for the yeast to do its job correctly.
There are two types of fermentation typically used by brewers. Many brewers use primary fermentation, which takes around 3-5 days when yeast converts most of the sugar into alcohol and carbon dioxide.
However, secondary fermentation is sometimes used by smaller breweries, as it takes at least two weeks or longer. The yeast works slower, conditioning the beer and reabsorbing any undesirable chemical by-products. The final product has improved clarity as there has been a reduction in the amount of sediment in the finished beer. It also often means the alcohol by volume (ABV) increases.
After fermentation, wort and yeast are mixed with water containing sterile air.
The function of the yeast is to consume the sugars created in the mash and turn them into alcohol and carbon dioxide (CO2).
Step 7. Conditioning
The conditioning process is responsible for ensuring that the beer is ready for sale, and usually lasts for around two weeks.Its purpose is to allow the beer to mature, for flavours and aromas to mellow, and aids in the clarifying process for a smooth finish.
Conditioning also helps to stabilise the flavour and aroma of the beer, so that it tastes the same every time you drink it. Beer that hasn’t been properly conditioned can taste sour.
Step 8. Filtering, processing and bottling
Next, a filtering process is used to remove unwanted by-products such as yeast, tannins and proteins from the beer that would give off flavours and haze. While many of these impurities will eventually precipitate out of the beer through ageing, filtering speeds up the process by removing them in minutes instead of weeks or months.
When the filtering process is complete, the finished product is made. The beer may then be put in a cask, in containers, bottles, or cans. Unfiltered beer can often be considered a bit of ‘craft’ as it keeps a more intense flavour.