THE EDITOR’S DESK :: PASTEURIZATION IN BREWING 101

by Harvey Gold on September 11, 2011

Loyal YBN participant, and a fine writer unto herself, Wendy Schweiger, posed a question on our facebook page. We were able to get this addressed by our friend, Mark Phipps, former brewmaster . Yet another reason why if you haven’t yet “liked” our YourBeerNetwork facebook page, you should.

That said, in the event you haven’t, or won’t, it’s our feeling you shouldn’t be penalized by being kept from this truly interesting conversation. So have at it…

Question for the assembled: Last week I found six-packs of Bell’s in my local grocery store in the massive section of unrefrigerated bottles. The packaging clearly stated the product was unpasteurized and was to be refrigerated at all times. I objected to the management, who was appalled (the beer manager was not on duty) and said he would look into it. How often does this happen? How many brands are still unpasteurized, where the storage temperature really matters? And is it a health issue or just an avoidance-of-skunkiness issue?

  • YourBeerNetwork Wendy, we’ve invited a couple brewmasters to throw in on this, as I suspect they’ll be far more articulate than we will on the matter. That said, to dig a bit, this is a nice beer piece that includes the pasteurization question, as posted by our friends at Bestnaturalfoods.com
    http://www.bestnaturalfoods.com/newsletter/organic_beer.html

  • Wendy Schweiger Veddy interesting. Thanks, Harv. I look forward to hearing more about this.
  • Mark Phipps Weighing in a little late on this one, but I have a couple of comments:

    A growing number of beers are packaged and sold without pasteurization. Most of the larger brewers use pasteurization or sterile filtration as the major methods for preserving packaged beers. This is not for health concerns, but insurance, of sorts, against changes in flavor due to possible living and active microbes in the beer. Normal filtration to clarify beer does not remove all yeast or microbes. Only micro-filtration can remove all microorganisms, but then subsequent packaging must be done aseptically in order to avoid the introduction of other beer spoilage bacteria.

    Pasteurization has always had detrimental effects on flavor since it involves heating the package to kill off anything living inside…much like the process of canning foods. For beer this means heating to 60 degrees Celsius (140 Fahrenheit) for 8-10 minutes. This cooks the finished beer and the flavor change is detectable both by trained and untrained tasters. Natural enzymes and vitamins are usually destroyed also by the heating. These are all reasons why many brewers choose not to do it. The risk is that retail people will not handle your product properly, as in Wendy’s case above.

    The good news for consumers is that beer is a poor medium for the growth of microorganisms for a number of reasons. Beer generally has a low pH (slightly acidic) and this greatly limits what can grow in it. Also the presence of alcohol (ethanol) combined with residuals from hops (hop oils and iso-humulones) act in concert as natural sterilizing agents.

    More good news: There are no known pathogens that can thrive in beer. Pathogens are microbes that can make you sick or produce toxins that would. Brewers mostly worry about “beer spoilage” microorganisms…wild yeasts, molds, or bacteria. These could alter the flavor or beer clarity, sometimes drastically, rendering the beer undesirable or undrinkable, but not dangerous. The mistake made by not refrigerating unpasteurized beer does not really endanger the consumer’s health, but it can certainly direct an assault on your taste buds and endanger the reputation of the brewer’s product.

  • Mark Phipps Oh, I forgot to mention that what brewers refer to as “skunkiness” is not just a general term for undesirable or old flavors. An actual skunk-like odor is sometimes found in beer due to a small chemical change in the bittering factor of hops (iso-humulone). This chemical change is brought on by exposure to light (specifically UV light) and the result is a sulfurous compound called methyl mercaptan…a similar chemical to that which is naturally produced and sprayed by skunks as a self-defense mechanism. This is one reason that beer is best preserved in brown or green glass bottles. Brown provides the best filtering of UV light, and green is a less effective filter. Clear glass offers no protection against “skunkiness”. Buyer beware.
  • Wendy Schweiger Thanks for all this background, Mark! It’s great to hear about it from the horse’s mouth instead of some ill-informed beer department manager in a retail setting that has no incentive to do the right thing by its customers.

{ 1 comment… read it below or add one }

Promise Orji January 26, 2014 at 10:36 pm

Why is it necessary to further pasteurize beer. Describe the methods that can be used for this and its effect on finished product. Analyze the pasteurization method discussed, explain the parameters and how important is it to product quality, water optimization and energy consumption?

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