The aftermath of yesterday's alcoholism has arrived, and my head is banging relentlessly. Sometimes, we come to realize that the quality of beer extends beyond just its taste and flavor, it encompasses the overall experience after consumption. Even the finest brew can become off-limits if it consistently results in a "terrible hangover." In this article, Tiantai will unveil the reasons behind beer causing these debilitating hangovers and how to improve beer quality in this regard during the brewing process.
The culprit responsible for these post-beer miseries is higher alcohol, also known as fusel alcohol. This term refers to alcohols containing more than three carbon atoms, a notorious presence in the alcohol and liquor industry. Higher alcohols are prominent by-products in the beer fermentation process and serve as key contributors to beer's aroma and flavor. The right composition and quantity of higher alcohols can enhance both the aroma and taste of beer, improving its overall quality.
Typically, the acceptable range for higher alcohol content in beer, following the fermentation process, is 60-90mg/L. If this content exceeds 120mg/L or the isobutanol exceeds 10mg/L, with an isoamyl alcohol content exceeding 50mg/L, it can lead to human poisoning, anesthesia, nerve congestion, dizziness, and what's colloquially known as "hangover" after beer consumption.
So, why might your beer contain excessive amounts of higher alcohol?
The first step is to check your yeast strains.
Different yeast strains have varying metabolic enzyme activities, resulting in different levels of higher alcohol production. When choosing yeast, pay attention to the specifications provided and choose a yeast strain with lower higher alcohol production.
Check the oxygen levels in the wort.
Wort oxygenation is essential for yeast growth and reproduction. When the oxygen in the wort is depleted, yeast transitions from the growth and reproduction phase to alcoholic fermentation, significantly reducing higher alcohol production. In practice, approximately 80% of higher alcohols are generated during yeast growth and reproduction, which occurs in the first two days of fermentation. Excess dissolved oxygen will promote yeast proliferation, thereby increasing higher alcohol production. To mitigate this, maintain dissolved oxygen at 8-10mg/L. Additionally, adjusting yeast quantity and reducing yeast proliferation can help inhibit higher alcohol production, aiming for a yeast cell count of 15x10/m.
Monitor fermentation temperature.
Research indicates that temperature profoundly influences higher alcohol production in beer. As temperature rises, yeast growth, reproduction, sugar and amino acid metabolism accelerate, increasing intermediate product α-keto acids levels. To control higher alcohol production, manage fermentation temperature and tank pressure. Implement strategies such as lower initial fermentation temperatures and controlled temperature increases during the later stages of primary fermentation to reduce diacetyl.
Determination of α-amino nitrogen content in wort.
Optimal α-amino nitrogen levels promote yeast reproduction and the production of the right amount of higher alcohols as essential nutrients. Excessive α-amino nitrogen causes rapid consumption of amino acids during yeast propagation, leading to an increase in α-ketoacids and subsequently, higher alcohols. Conversely, insufficient α-amino nitrogen forces yeast cells to synthesize amino acids through intermediate sugar metabolism pathways, resulting in more α-ketoacids. Therefore, it is advisable to maintain α-amino nitrogen content in 12 °P wort within the range of 180±200mg/L.
Beer quality is a multifaceted attribute, influenced by various factors. Different types of beer have different quality standards. With the craft beer industry's growth and evolution, consumers are becoming more discerning. To thrive in this market, brewers must not only invest in professional equipment but also continually enhance their brewing processes and maintain rigorous quality control standards to remain competitive.
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