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Breaking Down the Core Concept of Beer Freshness with microESR

Beer Freshness is more than a quality that enhances flavour; it’s a science of maintaining peak taste and aroma, and it’s something every beer lover wants to preserve. Traditionally brewers and consumers gauge freshness by looking at packaging dates and following storage guidelines. However, new technology, specifically microESR, is adding a new level of precision to understanding beer freshness.

In this blog Mangethe, Beer Freshness Manager here at FlavorActiV, answers some question to give us an insight into the science behind the microESR and how it is revolutionising our ability to measure and maintain freshness in beer.

What does Freshness mean in beer?

Freshness is simply defined as the way the brewer intended the beer to taste when it left the brewery. Every brewer wants their beer to taste as fresh as possible for the longest length of time, exactly as they intended. Fresh beer lacks what are known as matured tastes. Aged flavours are undesirable to both the customer and the brewer. These tastes have the capacity to entirely transform the beer’s profile and taste to something other than what the brewer intended. A FRESH beer is untainted by undesirable aging flavours.

Beer freshness is closely tied to the shelf life of a product. It is important to the brewer because it ensures that the consumer tastes an unadulterated product throughout its existence. This implies that the brewer may be confident that the beer’s flavour profile will not alter over the product’s lifetime. With globalisation, brewers want their products to be available all over the world, and beer freshness is a key tool for ensuring that beers in different regions throughout the world have an identical profile as the brewer intended.

More about this revolutionising technology…

What is a microESR and how does it work?

The microESR is an analytical instrument designed to measure free radicals, with a focus on the hydroxyl radical*, which is pivotal in oxidation processes. In beer production, the hydroxyl radical triggers lipid oxidation, causing the breakdown of beer components and resulting in unwanted aged flavours. Therefore, detecting and measuring hydroxyl radicals is crucial for preserving the quality and flavours of beer.

Since hydroxyl is a highly reactive free radical, scientists use a technique called spin trapping, with a compound known as a nitroxide to capture the hydroxyl radical. This approach allows for the measurement of these radicals at room temperature, without needing the sample to be frozen. By measuring the hydroxyl radical in the final beer product, brewers can predict the potential for the formation of unwanted aged flavours over the product’s lifecycle. Additionally, evaluating the hydroxyl radical in various brewing processes helps brewers identify which stages may significantly influence oxidation and the formation of aged flavours in the final product.

*A hydroxyl radical is a highly reactive molecule made up of one hydrogen atom and one oxygen atom with and unpaired electron.

Factors affecting beer freshness (and how microESR can help monitor them)

Beer freshness is influenced by the presence of transition metals such as ferrous iron and copper, especially when combined with heat, oxygen, and light. These elements can create challenges throughout the brewing process. Heat exposure in the brewery’s hot sections, oxygen presence at high temperatures, the infusion of oxygen into hot wort during boiling, and uncontrolled wort transfer all contribute to the development of aged flavours. The microESR is a tool that evaluates each step for its potential to produce these undesirable flavours, helping brewers identify weak points in their processes. By understanding which processes need optimisation, brewers can minimize the impact of the oxidation process on the final product’s taste. While many factors influence beer freshness, they generally fall into three categories: Process, Plant (brewery), and Raw Materials (brewing and cleaning). The use of microESR enables brewers to refine any of these areas by measuring the production of free radicals.

Which taints are caused as a result of the lack of beer freshness?

Several common taints in beer are influenced by oxidation, leading to undesirable aged flavours such as papery (cardboard), catty (mousy), acetaldehyde (green apple), and honey-like (sweet) notes. High oxidation levels during brewing, poor fermentation management, and excessive oxygen during packaging contribute to these flavours. Additionally, poor fermentation management can result in spicy (phenolic), sweet (banana, red apple), H2S (rotten egg), and high diacetyl (butterscotch, buttery) flavours, indicating high oxidation and poor fermentation practices.

High temperatures and poor management of the brewhouse (the hot part of the brewery) also cause taints, often due to poor management of raw materials and abnormal heat loads. Examples include DMS (sweet corn), phenylacetaldehyde (honey, rose), methional (rotten/cooked potato), furfural (bready, almond-like), and benzaldehyde (almond, sweet, caramel). These flavours are oxidation-related and result from high temperatures and poor brewhouse management.

While the topic is extensive and intricate, focusing on a single component in the brewing process can provide brewers with valuable insights into their brewery’s potential for producing aged flavours. By carefully analysing and understanding their processes, they can identify areas to reduce the production of staling flavours and improve the overall quality of their beer.

Can the microESR define which part of the brewing process needs improving, if so, how?

There are several procedures used to measure the taints and specific flavours imparted by the oxidation process in beer, specifically. However, these methods often lag and do not provide insight into where in the process these flavours are introduced. They measure the “after-the-fact” effects of oxidation and lack the ability to build insight and predictive capacity for determining the production of aged flavours in beer.

microESR, on the other hand, measures the “precursors” involved in the formation of aged flavours rather than the final flavours, giving it a distinct advantage. By measuring free radical production throughout the process, microESR allows brewers to identify which processes have the highest potential to contribute to the development of aged flavours. This method is not lagging, has predictive potential, and enables brewers to pinpoint weaknesses in their processes that contribute to the oxidation of the final product, resulting in an aged flavour profile.

High levels of oxidation in the brewhouse are undesirable. microESR can track which processes produce high levels of free radicals, allowing these processes to be optimised by adjusting brewery operations and managing raw materials. This helps brewers predict whether the final product will have a low or high potential for developing an aged flavours profile, both in the early and later stages of its shelf life.

How is the microESR enhancing Brewing and Packaging Processes?

The measurement of free radicals allows brewers to identify which processes most significantly impact the production of aged flavours in the final product. These processes can then be managed, optimised, and controlled using microESR technology. Managing dissolved oxygen (DO) levels during packaging is crucial for all breweries, as high DO levels can affect the beer’s flavour later in its shelf life. By using microESR in the packaging process, brewers can add a predictive layer, enabling them to relate and predict packaging conditions to the production of aged flavours in the beer.

What functions/applications of the microESR can be used by Brewers looking to maximise beer freshness?

Actions to Improve Beer Freshness Using microESR

Benchmarking the Brewery:

• Identify processes with weaknesses that contribute to the development of aged flavours.
• Focus on areas with the highest potential for improvement.

Benchmarking the Main Beer Brand:

• Map the production process and evaluate the final product’s freshness and sensory performance.
• Relate the development of aged flavour profiles to the freshness values of the product.

Improving Processes:

• Enhance processes with identified freshness weaknesses.
• Integrate optimisation actions into routine brewery operations.

Monitoring Flavour Profile Improvement:

• Track the beer’s flavour profile post-production (during aging).
• Ensure the development of aged flavours is delayed for 6, 9, or 12 months.

Using microESR to Measure Freshness

Freshness Index:

• The Freshness Index, measured using microESR, directly correlates with the beer’s shelf life.
• Higher Freshness Index values indicate a longer shelf life and fresher beer.
• This index can be compared to the product’s immune system: a higher index means the beer will take longer to develop aged flavours.

Reducing the Oxidation Index:

• Increase the Freshness Index by reducing the Oxidation Index in critical processes.
• Lowering the Oxidation Index indirectly boosts the Freshness Index of the final product.

Improving Sensory Profile

Oxidation Rate:

• Unlike the Freshness Index, the Oxidation Rate can be measured throughout the product’s lifecycle, including during brewery processes.
• Aim to keep the Oxidation Index and Oxidation Rate as low as possible for each process.
• After production, ensure the Freshness Index is high (indicating a good immune system) and the Oxidation Rate is low (indicating low potential for free radical production).

By focusing on these actions and measurements, brewers can significantly enhance the freshness and shelf life of their beer, ensuring a higher quality product for consumers.

The future of beer freshness using microESR Technology

microESR technology holds great potential for predicting product shelf life through the use of predictive data models. By leveraging big data technologies and advanced data models, microESR data can be utilized to forecast the lifecycle of products. This predictive capability can significantly enhance the freshness of products in the marketplace, thereby improving the consumer experience with beer and other beverages.

microESR technology can also be applied to other beverage sectors, such as Cider, Soft Drinks, Wine and the new Ready-to-Drink beverage sector. Another import industry that has benefit from the use of microESR is the Olive Oil Industry.

By expanding the application of microESR technology across various industries, we can ensure better product quality and longer shelf life, ultimately enhancing consumer satisfaction.

How are the functions of the microESR going to change the way brewers work?

Breweries will benefit from improved resource management for producing fresh beer. Instead of trying to enhance every process simultaneously, brewers can systematically optimize each process, making the best use of their resources. This approach allows for a better understanding of the brewery’s limitations in producing beers that resist developing aged flavours early in the product’s storage lifecycle.

With a greater focus on oxidation, breweries can go beyond just managing sensory and flavours profiles. By using microESR technology, they can effectively manage the brewing process to produce beer that remains fresh for up to 12 months. This targeted approach ensures that resources are used efficiently, and that the final product maintains its quality over a longer period.

What is the future of beer freshness?

The future of beer freshness lies in achieving a 12-month fresh beer across various beer styles. Currently, the market struggles to provide this, with the best offerings occasionally reaching only 4 months of freshness. Enhancing beer freshness will improve the consistency of sensory performance across different batches within the same brand, an area where the industry currently falls short. By extensively using advanced technology, the industry can significantly improve these crucial aspects of beer flavour and aroma during aging.

Conclusion

Using a microESR to track factors such as oxidation, can improve the overall quality and freshness of beer. This provides brewers with insights into managing the freshness over a beer’s lifecycle, from the very beginning of production all the way to distribution.

If you want to hear more about measuring and optimising your beer freshness contact FlavorActiV today!