What Is Flash Pasteurization in Beer Making?
Pasteurization is a hot topic right now, with more people wondering if pasteurization is even necessary, and if it does any harm to the food or beverage involved.
For many years, brewers have been pasteurizing beer to varying degrees of success, which brings up the question, “what is flash pasteurization in beer making?”
Let’s take a look.
What Is Pasteurization?
Pasteurization began in the early 1800s with Louis Pasteur, father of microbiology.
Pasteur brought us the concept of germs, as he could see them through his microscope, and he warned us about what was making us sick – all the germs!
It was indeed from Pasteur that germ theory sprung, the idea that it is germs that make us sick, and not the state of our bodies.
It was thanks to Pasteur and germ theory that we got antibiotics, which kill good and bad bacteria, vaccines, which were designed to prevent us from catching the diseases that were killing people, and, today, things like bleach household cleaners and hand sanitizers.
It was also thanks to Pasteur’s work that doctors started washing their hands before surgery, stopped smoking in the operating room, and began to don masks before opening up a patient.
Clearly much good came from Pasteur.
Still, his contemporary, psychologist Claude Bernard, presented a counterpoint to germ theory.
He posited that the human body, the terrain, had much to do with how a germ or a disease would be handled – whether a person would get sick or not after exposure, and whether a person would live or die after getting sick, as well as how severe an illness would be.
How else could we explain one person falling deathly ill from exposure and another showing no symptoms at all to the same exposure?
This theory of Bernard’s has come to be known as terrain theory.
For better or worse, the debate still rages on today.
Another lasting result of germ theory was pasteurization.
Pasteur was a lover of both beer and wine, and he wondered about why beer would sometimes make people sick.
He discovered that beer left on shelves at warmer temperatures for longer periods of time would attract spoilage bacterium that could make the drinker sick.
The solution he proposed was pasteurization, heating up the beer right before fermentation ended and bottling or kegging began.
What Is Flash Pasteurization?
As Pasteur recommended it, the beer only needed to be heated up to boiling, approximately 160 degrees Fahrenheit, for 30 seconds at the most, and then it could be quickly cooled down to refrigeration levels for storage.
This process came to be known as flash pasteurization because it happened in a flash.
Then, another scientist came along later in the 1800s and invented what seemed to be a simpler process for pasteurizing beer.
Nicolas Appert, another Frenchman, determined that the same effect of killing off potential spoilage bacteria could be achieved through heating the beverage in its container at a lower heat level for a longer time.
The process, technically called Appertisation but more commonly known as tunnel pasteurization, calls for the bottled or canned beer to sit in a heated bath of 140 degrees Fahrenheit for up to 30 minutes before being cooled down to refrigeration temperatures.
Of course, dairy farmers began to follow the same process of pasteurization, either flash or tunnel, and the rest, as they say, is history.
Do We Need to Pasteurize Beer?
Some, of course, have rejected the need for pasteurization, especially when it comes to small batch beer.
Indeed, most small craft brewers will not pasteurize beer and will in fact market their beer as “unpasteurized.”
The same argument is made for grass fed raw milk, that many more nutrients remain in the unpasteurized products than do in pasteurized ones, and that the flavor is better, richer, and more natural.
Whether this declaration proves to be true will likely need much more study, blind tests, and consideration.
The bottom line when it comes to beer is that the consensus among brewers is that small batch beer does not need to be pasteurized as it will likely be consumed within a short period of time, less than two months, and either onsite or close to the original location of production.
The real goal of pasteurization is to preserve beer and extend its shelf life for large batches that will travel and ship.
Indeed, it would be silly for large, commercial brewers to go to all the trouble of establishing a consistent product with a recognizable brand only to take the chance a loyal fan gets sick from unpasteurized beer that sat on the shelf for too long and spoiled.
Pasteurization is the reason we can usually safely say that beer doesn’t really “go bad.” It will just go flat or dull.
Still, lack of pasteurization does not guarantee beer will go bad. Of course, we always have alcohol and hops in the mix to prevent many toxins and microbes from harming human health.
But with larger batches, it is nice to have the backup.
How to Pasteurize Beer
If you, as a brewer, get to the point where you will be shipping your product across the country, the continent, or overseas, or you find yourself making larger and larger batches, pasteurization may be something to consider, just to be safe.
You can choose between either flash pasteurization or tunnel pasteurization.
The advantages of flash pasteurization are many, including that the process is quick and easy and that the equipment is relatively inexpensive and can be installed quickly.
Tunnel pasteurization can take 3 times as long to install and be 3 times as expensive.
Still, the benefit of tunnel pasteurization is that you can follow through with the entire brewing process and simply pasteurize the bottles, cans, or kegs. You never have to worry about downstream contamination.
With flash pasteurization, there will always be the (miniscule) chance that your beer could encounter spoilage bacteria between the pasteurization and the final bottling.
It is, as always, a decision you will have to make based on your own needs and goals.
Cheers!
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Sources:
- https://cbp.goodnature.com/beer-pasteurization-history-methods-equipment
- https://vinepair.com/articles/unpasteurized-beer-explained/
- https://www.frontiersin.org/articles/10.3389/frfst.2021.798676/full
- https://www.anchorbrewing.com/blog/ask-bob-brewer-pasteurizing-craft-beer/
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