Step 1 – Malt Milling
To make beer, we need sugar, which is obtained from sprouted barley. The fermentable sugar in the malt is found in the outer shell of the inner core, where it exists as starch. We need to open the shell to expose the starch for transformation.
When purchasing a grinder for brewing, it is recommended to choose a grinder with an adjustable drum. This allows you to control the degree of malt grinding. If the malt is ground too finely, it will make the wort too thick and difficult to filter, which makes it challenging to transfer the malt mash (wort) into the next brewing tank.
Step 2 – Mashing
Mashing involves mixing ground malt with hot water to convert the starch in the grain into fermentable sugar. If the mashing process is completed at a specific temperature, it is called infusion mash. This is common in British ale beer brewing, where saccharification occurs at 65°C. The mash is kept at this temperature for one hour, allowing the enzyme in the malt to release maltose from the grain.
However, for certain beers, a step mash is recommended. In a step mash, the temperature of the mash bed is raised at different stages to break down different parts of the starchy endosperm.
Proteases at 35°C–45°C (95°F–113°F): Break down the protein matrix that holds the starch granules.
Glucanases at 45°C–55°C (113°F–131°F): Break down the hemicellulose gums.
Amylases at 61°C–67°C (141.8°F–152.6°F): Break down the starch granules and larger sugar molecules into fermentable sugars.
Before lautering, it is common to perform a “mash out” by raising the temperature of the mash to about 77°C (170°F). This stops most enzymatic activity.
Step 3 – Lautering
Lautering involves filtering the mash to rinse away the remaining sugar. If not rinsed, a significant amount of sugar will remain in the malt. Filtration also helps achieve good extraction efficiency. It is best to collect the clear wort for transfer to the brewing pot.
When filtering, it is important to match the incoming water with the outgoing wort. Adding water too slowly may cause the mash bed to dry out, while adding water too quickly can cause the mash to overflow. These conditions can lead to problems during the brewing process and affect efficiency.
Step 4 – Wort Boiling
Boiling is a key process in beer brewing and involves several important reactions:
Boiling stops enzymatic activity – it effectively deactivates the enzymes, ensuring a consistent wort composition in the fermentation tank (FV).
Boiling sterilizes the wort – it eliminates unwanted microorganisms, providing a clean environment for the yeast.
Boiling allows the addition of hops – hops contain alpha acids that contribute bitterness to beer. Boiling the hops isomerizes the alpha acids, making them easier to dissolve and impart a bitter taste.
Boiling facilitates the evaporation of volatile compounds – certain compounds produced during germination, such as S-methyl-methionine (SMM), can lead to off-flavors in the beer. Boiling helps remove these compounds.
Boiling promotes protein coagulation – during boiling, proteins interact with tannins and form clumps that gradually settle at the bottom of the container.
Step 5 – Clarification
During boiling, proteins coagulate at two points in the kettle. The “hot break” occurs at the beginning of the boil, forming scum on the surface of the wort. The “cold break” happens when the wort is rapidly chilled on its way to the fermentation tank, resulting in a soup-like appearance. Many modern breweries also utilize a whirlpool after boiling to further clarify the wort.
In a whirlpool, the wort is pumped rapidly, creating a vortex. This allows hops and trub (solid particles) to form a cone in the center of the kettle. When transferring the wort to the fermentation tank, it is done from a point above the trub cone, leaving the solids behind.
Step 6 – Cooling
After boiling, the wort needs to be cooled before yeast can be added and fermentation begins. The clarified wort is passed through a heat exchanger to the fermentation tank, where it quickly cools to a temperature between 7°C and 35°C (depending on the beer style).
The heat exchanger works by circulating cold water or glycol on one side, while the hot wort enters from the other side. The cold water/glycol absorbs heat from the wort without coming into direct contact with it.
Step 7 – Fermentation
Once the wort is cooled and transferred to the fermentation tank, yeast is added to initiate fermentation. The first stage of fermentation, known as primary fermentation, begins as the yeast becomes active and consumes the sugar in the wort, producing alcohol and carbon dioxide. As sugar is converted into alcohol, the liquid gradually transforms from sweet to finished beer.
Depending on the yeast strain used, certain flavor compounds such as phenols and esters may be produced, adding unique characteristics to the beer. For example, hefeweizen-flavored beer contains isoamyl acetate and 4-vinyl guaiacol found in Belgian wheat beer.
ACE 7BBL fermentation tanks
After 5 to 7 days of fermentation, the fermentation speed slows down significantly as the yeast consumes most of the sugar. The yeast, along with hop particles, proteins, and other solid substances, settles to the bottom of the fermentation tank.
During this period, it is possible to remove some of the solids that have accumulated at the bottom of the tank, but it’s important not to remove too much as valuable yeast may be lost.
Fermentation may be completed within 7 to 10 days, although certain beer styles may require longer fermentation times. Once fermentation is complete, the beer can be cooled further to facilitate the removal of more yeast and solids. The collected yeast can be reused for subsequent brews. Conditioning is the next step for the beer.
Step 8 – Conditioning
Fermentation is a complex process that may result in some undesired sediment in the beer. Conditioning is necessary to improve the beer’s clarity and remove unwanted flavor compounds. Additionally, conditioned beer tends to become more delicate and full-bodied.
During conditioning, the beer is stored at a temperature of 32°F to 39.2°F (0°C to 4°C), causing proteins and polyphenols in the beer to condense and settle at the bottom of the bright tank. This process enhances the beer’s appearance and body.
Step 9 – Packaging
Once the beer has undergone conditioning, it is ready for packaging and sale. Before packaging, various checks are conducted to ensure that the beer meets quality standards.