Today, we will discuss the key points to consider when fermenting beer. These include the type of yeast used, the concentration of wort for fermentation, whether it is commercial or home brewing, and the desired final alcohol concentration.
The Nature of Brewing
Why is it important to use professional equipment for commercial craft beer production or to engage in home brewing? Home brewing allows for smaller batches and greater flexibility, enabling the brewer to make specific changes, additions, and manipulations to the fermentation process (such as adding sugar to increase alcohol production). On the other hand, the fermentation process in professional equipment is not easily adjustable.
It is important to remember that sugar is a source of alcohol. Without sugar, there can be no fermentation and therefore no alcohol. So, the more sugar, the better, to some extent. However, two aspects of yeast selection play a crucial role here: sugar tolerance and alcohol tolerance. Sugar tolerance refers to the percentage of Brix at which yeast die due to excess sugar, whereas alcohol tolerance refers to the percentage of ABV at which yeast die due to excessive alcohol. When the sugar concentration is high, it acts as a desiccant and dehydrates the yeast cells, causing them to die. Therefore, instead of adding sugar to the wort, it is best to adjust the sugar content by increasing the initial wort concentration (OG).
As mentioned earlier, yeast selection affects the fermentation process from the beginning in terms of alcohol tolerance and sugar tolerance. When brewing low-alcohol beers with a wort that can produce 9% ABV, there is no need to use yeast tolerant of 18% ABV. However, when brewing beer or spirits with high alcohol content, using yeast with low alcohol tolerance can negatively impact yeast activity during fermentation, resulting in failure or insufficient fermentation.
The pH of the Wort
Just like sugar and alcohol tolerance, each type of yeast has an optimal pH range for effective fermentation, which is usually related to the ingredients used. Typically, the pH of the wort before fermentation ranges from 5.2 to 5.6. As fermentation progresses, the pH gradually decreases. Therefore, it is essential to check the pH of the cold wort before fermentation starts to ensure it does not affect the fermentation process.
Sufficient Oxygen in the Fermenter?
Yeast generates energy through its metabolism during fermentation, which occurs through both aerobic and anaerobic stages. In an aerobic environment, yeast respirates and reproduces. This allows us to use small amounts of yeast in large batches. In cases where the beer has insufficient oxygen content, wort oxygenation should be performed before fermentation. However, most beer fermentations are conducted in closed fermenters, isolating the yeast from the air. This allows the yeast to undergo forced fermentation once all the oxygen in the tank has been consumed, creating a carbon dioxide-rich environment.
In general, ales are fermented at higher temperatures (18°C-22°C) compared to lagers (7°C-16°C). Heat acts as a catalyst, increasing the activity and movement of particles in the beer. The higher the temperature, the faster the yeast can consume sugar and convert it into alcohol and CO2. However, high temperatures can also lead to issues.
Warmer temperatures cause yeast to produce more fusel alcohols, which are potent alcohols that can give the beer a burning taste. They are often compared to low-quality alcohol that overpowers the flavors of the beer’s main ingredients.
Warm yeast can also promote the production of more acetaldehyde. While this compound is present in small amounts during normal fermentation, excessive amounts can result in beer having green apple flavors.
By following the above steps in planning and executing beer fermentations, the likelihood of fermentation issues can be reduced, resulting in improved alcohol yields and flavor profiles.
Turnkey Craft Brewery
Whether you are engaged in home brewing or commercial brewing, paying attention to the aforementioned factors is crucial for brewing delicious beer. It is also essential to familiarize yourself with the beer fermentation and brewing process as much as possible. If you plan to open your own brewery, you can contact ACE Craft for professional technical support and beer equipment integration services, enabling you to brew even better beer with peace of mind.
Get a turnkey solution for brewery equipment. If you are planning to open or expand a brewery, you can directly contact us. Our engineers will design and manufacture brewery equipment tailored to your brewing process. We also provide a complete turnkey solution, including customized solutions for expanding your brewery.