It's hard not to notice the momentum that NABLABs seem to be gaining and how the popular press continues to report on this rising sector of the market. It's also hard not to notice discussions about the potentials for pathogens in these beverages.
Like many brewers, my educational journey began in food science. One of my favorite food science classes while an undergrad at Virginia Tech from 1988-1991 was food microbiology. Dr. Cameron Hackney, an expert in pathogenic microbes associated with seafood, delivered enthralling lectures about all the nasty bugs found in the food world. This topic grabbed my attention and turned me into a very cautious consumer. Over time I relaxed and developed quite the taste for sushi and oysters. When I became ill at the 2007 CBC in Austin, Texas, I quickly self-diagnosed myself with Vibrio from raw oysters and began pounding electrolytes and taking Imodium, losing only about 36 hours from the conference and a few pounds in ejected stuff from my body!
In the late 1990's, I made a few batches of hard cider over a 3-year period from juice purchased at a great orchard in Marionville, MO. This was after the Odwalla juice outbreak involving E.coli O157:H7 that sickened 66 people, caused the death of one child, and changed the juice world. After this outbreak, all juice producers were required to pasteurize juice and many small orchards producing apple juice/cider stopped production because the CAPEX was not worth the squeeze.
As NABLABs continue to grow in popularity, brewers are smart to be cautious of the risks and smart to implement proper practices. But has the risk been over-stated? Vibrio is found in unpolluted saltwater and is an obvious organism associated with shellfish. E.coli is found in animal feces and can contaminant fruits and vegetables. The Odwalla case was linked to fallen apples picked from the ground, so-called grounders, that were contaminated by deer feces. Cases of hemorrhagic E.coli in vegetables have been tied to contaminated water used for irrigation. The same is true of Salmonella outbreaks in fresh produce, like the current cucumber outbreak. And one of the landmark cases of foodborne listeriosis was tracked to cabbage contaminated with sheep manure used for fertilizer by an organic farmer.
Serious question for this group? What are likely vectors of E. coli, Listeria, Salmonella, and other pathogens in beer? It's one thing to inoculate pathogens into beer to determine the potential for danger, but it's also important to understand sources of these bugs.
Following the Odwalla outbreak, FDA mandated single-strength juices be processed with a 5D process (5 log reduction). Although the government does not tell processors how to do this, they do reference a paper in their industry guidance document. The study referenced is titled "Thermal Inactivation of Stationary-Phase and Acid-Adapted Escherichia coli O157:H7, Salmonella, and Listeria monocytogenes in Fruit Juices" and does provide a recommended process based on D-values of pathogens actually found in fruit juices and involved in outbreaks (we don't have this sort of history in beer). The 5D process is a staggering 3 seconds at 71.1C - in beer terms that's 2, yes TWO, pasteurization units! No brewery pasteurizes at such a low level because the purpose of beer pasteurization is the destruction of spoilage organisms that are indeed present at concentrations much higher than 10,000 cfu/mL. It's important to point out that the D-values used to provide juice process guidance align with recent work from Greg Rachon's group at Campdem BRI. The authors of this juice study state:
"Considering that it is not likely to find 10^5 pathogens per ml of juice produced under good manufacturing practices and good sanitary plant conditions, this process is very conservative. During an outbreak of salmonellosis from orange juice contaminated with Salmonella Hartford, counts recovered from the juice were below 10 CFU/100 ml of juice (10). Moreover, the process calculation was based on
data for acid-adapted cells; cells that have not adapted to a stress shock would be more sensitive."
"Shelf-stable, hot-filled juices are processed to inactivate microorganisms such as molds, yeasts, and other bacteria that may spoil the product. A typical pasteurization process might be 90C for 2 s, followed by filling at 85C and holding at that temperature for 1 min before cooling. Without taking into account the cumulative lethality during the cooling period, shelf-stable, hot-filled juices receive a lethality sufficient to inactivate 50,000 logs of acid-adapted vegetative pathogens such as E. coli O157:H7, Salmonella, and L. monocytogenes. There is, thus, no question about the microbial safety of these juices."
You may be wondering why the long post. I'm sitting in Chicago O'Hare on a Saturday afternoon and was enjoying some very nice craft-brewed NA last night in a small brewery in Pittsburgh who is finding lots of success brewing beers to complement their great range of alcoholic beers. Producing NABLABs is well within the reach of any brewer brewing great beer. And the thermal process requirements are not rocket science given the right plan of action, proper data collection, and lab testing.
Food for thought!
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Ashton Lewis
Manager of Training and Technical Support
RahrBSG
MBAA District Great Plains, Technical Chair
Springfield, Missouri
(417) 830-2337
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