Nitrogen Generation: The role of nitrogen in breweries

There are many components involved in the successful brewing of beer. Nitrogen generation is especially important since nitrogen needs to be present to prevent oxidation during the brewing process.

 In this article, we will cover the importance of having an optimally functioning nitrogen generator on-site for breweries, the science behind it all and how Maziak can help.

The role of nitrogen in beer brewing

Nitrogen is vital in many different ways when it comes to the brewing process and in recent times, more breweries are adapting to replace CO2 with nitrogen- we will talk more about this later. Below are some of the ways in which nitrogen is used in breweries:

Cleaning

The fermentation process involves adding yeast to the sugary liquid called Wort; the yeast absorbs the sugar and leaves behind alcohol. Nitrogen is added when the fermentation vessel is cleaned to prevent any chemicals from coming into contact with oxygen, as this would lead to oxidation, which can lead to the alcohol having undesirable flavours and aromas.

Nitrogen also supports yeast metabolism, which is advantageous during the fermenting process.

Pumping

The beer gets passed through a series of tanks during the brewing process, for which a pressure source is needed. Nitrogen is the best choice for facilitating this pressure transfer as it does not risk adding oxygen. Additionally, since it is an inert gas, it does not affect the carbonation of the beer; if CO2 were used, it would significantly affect the taste.

Maintaining dissolved oxygen levels

Since oxygen is an essential nutrient for the growth of yeast, there needs to be a certain amount of dissolved oxygen (DO) in the Wort before it enters the fermenting vessel without increasing the risk of oxidation. Nitrogen gas is the perfect solution, as it is an inert gas that will ensure the DO level remains the same throughout the fermenting process.

Maturing

Similarly to the cleaning process, nitrogen is used to prevent the taste and overall stability of the beer from being impacted by ambient oxygen. The maturing tank, where beer is given time to stabilise after fermentation, is purged with nitrogen before the beer enters it.

Carbonation

The application of nitrogen at this stage is less about prevention and more about enhancing the flavour and appearance of the beer that has been brewed. When mixed with CO2, nitrogen can positively impact the carbonation processes by helping to produce finer bubbles, which, in turn, can give the beer a smoother texture and creamier mouthfeel.

Packaging

Even when the brewing process is complete, nitrogen gas remains a useful component as it can be used to fill cans and bottles before and after they are filled with beer to prevent unwanted oxygen from entering and triggering oxidation at the final stage, which can impact the flavour and texture of the beer.

Nitrogen gas can also be used as a propellent for kegs. In the same way that nitrogen is used to push beer through the tanks during the brewing process, it can facilitate the movement of beer from the keg to the bar tap.

Nitrogen vs CO2 and the benefits

CO2 is another inert gas that is commonly used to help with the brewery process. However, nitrogen outweighs CO2 in many ways:

• Nitrogen is cheaper due to its higher availability and is less dense than air, so less is needed
• Nitrogen is less soluble in water, which means it will not affect the CO2 balance of beer
• CO2 is an inert gas to a degree, but it is more susceptible to becoming corrosive in the presence of moisture compared to nitrogen
• Unlike CO2, nitrogen is not a greenhouse gas and doesn’t contribute to a brewery’s environmental footprint
• Nitrogen and CO2 have a purity of 99.9%, but whilst the 0.1% for CO2 can consist of substances from other chemical processes, the 0.1% for nitrogen will contain only gases.

How Maziak can help

We can supply state-of-the-art equipment for on-site nitrogen generation that has been manufactured by Atlas Copco and help microbreweries:

• Reduce safety hazards by eliminating the need for nitrogen to be transported in bulk using large metal cylinders.
• Meet demand easier because of the flexibility that on-site nitrogen generation offers
• Save money by setting nitrogen purity as needed instead of purchasing nitrogen with very high purity
• Eliminate unnecessary tasks such as ordering, storage and replacement of cylinders that come with purchasing nitrogen from an external source
• Increase sustainability by eliminating the need to have purchased nitrogen delivered

If you own a microbrewery and are interested in having an on-site nitrogen generator, you can get in touch on our contact page, and a member of the Maziak team will get in touch with you as soon as possible to discuss your nitrogen requirements. Alternatively, if you have a question about any of our other services, leave us your enquiry and we will try to help in whichever way we can.