6 Reasons Why Fermenting Under Pressure Is Better

Today, many home brewers feel fermenting under pressure is better than other methods. Fermenting under pressure is fermenting using a closed and pressurized vessel that traps the CO2 inside and naturally pressurizes the system. So, why is fermenting under pressure better?

Fermenting under pressure is better because it makes the beer brewing process faster and cheaper. The process is also cleaner and more straightforward than traditional fermenting. In addition, it prevents beer oxidation and produces less krauser (foamy head). 

In this article, I’ll explore all the reasons mentioned above in detail. By the end of the article, you’ll understand why fermenting under pressure is better than other methods. Read on.

1. Fermenting Under Pressure Is Better Because It’s Faster

Investing in a pressure fermenter is vital if you want to venture into fermenting under pressure. Such a fermenter ensures that the under pressure fermentation process is safe and efficient. Once you have the right equipment, you’ll discover that fermenting under pressure is faster than fermenting traditionally.

The fermentation process could take two weeks or more when fermenting traditionally, depending on your desired results. However, fermenting under pressure is slightly faster; the process may take about eight days. 

The reasons why fermenting under pressure is more rapid are the following:

  • The fermenter is tightly closed and pressurized, thus trapping the CO2 inside. It’s unlike traditional fermentation, which allows CO2 to escape from the fermenter through a blow-off tube or an airlock.
  • The CO2 trapped inside the fermenter naturally pressurizes the system further, thus increasing the fermentation process. 
  • Fermentation occurs at higher temperatures than usual because of the pressure in the fermenter.
  • You can increase the temperature of the fermenter to speed up the fermentation process further.

As a home brewer, it’s good to know that beer brewing takes time and patience is vital. 

So, by reducing the fermenting period, you save on the waiting time. 

It’s good to note that faster fermentation does not compromise the beer’s flavor.

2. Fermenting Under Pressure Is Cheaper

With the right equipment, fermenting under pressure becomes cheaper than standard fermenting. The reason is that when using under pressure fermenting, the fermenter traps the CO2 you need to carbonate the beer inside

The under pressure fermenting equipment has a spunding valve that lets you naturally carbonate the beer in the fermenter. You just set the pounds per square inch (PSI) of pressure you desire on the valve and allow the beer to ferment away. For instance, a PSI of 10 to 15 is quite good. 

As a result, when you naturally carbonate your beer by fermenting under pressure, you don’t have to buy CO2 to add to your beer forcibly. You thus save money on the production costs.

This process differs from traditional fermenting, where it takes about two weeks for the beer to carbonate naturally. This long waiting period can push you to buy CO2 to carbonate by injecting the pressurized CO2 into the beer forcibly. 

Buying CO2 to carbonate the beer is an additional cost to the brewing process.

3. Fermenting Under Pressure Prevents Oxidation in the Beer

As a brewer, it’s best to avoid oxidation in your beer. Oxidation happens when you allow oxygen to interact with the fermenting yeast. If oxygen interacts with the fermenting yeast, it can give the beer an unpleasant, papery flavor even if you have the appropriate equipment and the best beer kits

When fermenting under pressure, the system is closed, so oxygen can’t interact with the fermenting yeast.

In addition, with under pressure fermenting, if you want your beer to have a higher alcohol content, you don’t have to pour the beer into another container for secondary fermentation. You need only leave the beer in the fermenter for a more extended period, and the alcohol content will increase. 

By leaving the beer longer in the fermenter for secondary fermentation, you prevent oxidation in the beer. As a result, you get a higher-quality beer. 

In addition, the beer has a longer shelf life as it takes longer to expire.   

4. Fermenting Under Pressure Is Cleaner

You should ensure that everything you use when brewing is clean to prevent your beer from getting contaminated or infected. One of the main advantages of fermenting under pressure is that the fermentation happens in one tightly closed vessel

You don’t expose the beer to air, and there is minor handling, thus preventing contamination and infection of the beer. 

However, in the traditional fermentation method, you must transfer the beer to another vessel for secondary fermentation. Doing so can expose the beer to contaminated air.

In addition, during the transfer process, there is a lot of handling, which could infect your beer. Infected beer could be harmful depending on the degree of contamination. 

5. Fermenting Under Pressure Produces Less Krausen

When fermenting beer traditionally, the foam on top of the fermenting beer (krausen) takes quite some space in the brewing vessel. The reason is that the traditional fermenting process is vigorous. The large amount of krausen decreases the amount of beer in the fermenter. 

However, when you ferment under pressure, the process is less vigorous, and the beer thus produces less krausen. 

When the fermenting process produces less krausen, you can brew a larger volume of beer in the fermenter to last for a longer period. 

6. Under Pressure Fermentation Makes Brewing Easier

Fermenting under pressure is better than traditional fermenting because it makes brewing easier.

Below is a table showing that fermenting under pressure is more straightforward than fermenting traditionally:

Fermenting Under PressureFermenting Traditionally
You don’t need to transfer the beer to another vessel for secondary fermentation.You have to transfer the beer to another container for secondary fermentation.
There’s natural carbonation, so you don’t have to add CO2 to the beer forcibly.You may have to forcibly add CO2 to the beer as CO2 escapes during fermentation.
You can serve the beer from the fermenter to the glass without using other vessels.You have to transfer the beer to other vessels, such as bottles; it consumes time and energy.

So, there you have it. It’s clear from this table that when you ferment under pressure, the effort you put into producing the beer reduces. 

About HomeBrewAdvice

Hello, my name is Simon. Together with a group of writers I write about brewing beer and making wine. We all share a passion for the great things in life, such as making stuff from scratch.

The business of HomeBrewAdvice is to bring you great information, stories and product reviews from brewing at home, and making wine


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