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Wine Quality and Safety 101
by Linda L. Leake, MS
It’s ancient news that wine is a global phenomenon.
Wine has flowed across many seas since it was first produced 8,000 years ago. Archaeological evidence suggests that the earliest known production of wine, made by fermenting grapes, occurred about 6,000 BC in the area now known as the country Georgia.
Cut to the present. Total 2012 wine production worldwide was a whopping 6.56 billion gallons, according to the Demeter Group’s State of the Wine Industry 2013.
According to the Food and Agriculture Organization, considering 2011 production, the top wine producing countries based on volume, are: 1. France, 2. Italy, 3. Spain, 4. U.S., 5. China, 6. Argentina, 7. Australia, 8. Chile, 9. South Africa, and 10. Germany.
There are wineries operating in all 50 states. WinesVinesDATA identified 7,498 wineries in the U.S. in 2012. Fewer than half the wineries are in California, reflecting the explosion of wineries throughout the other states. Twelve states have more than 100 wineries, with California (3,542 wineries), Washington (670), Oregon (544), New York (306), and Virginia (222) topping that list.
Total U.S. wine production reached 752.4 million gallons in 2012. Despite growing winery numbers in other states, California bottles more than 88 percent of the nation’s wine, 662.8 million gallons in 2012, says the Wine Institute.
In 2012, U.S. wine consumption was 2.7 gallons per person, and total U.S. consumption was 856 million gallons, a record high, reports the Wine Institute.
Another milestone of note: France consumed 742.3 million gallons of wine in 2013, a 7 percent decline over 2012, while the U.S., by comparison, consumed 768.7 million gallons, a 0.5 percent increase. That makes the U.S. the biggest internal market in the world in terms of volume, according to the Paris-based Organisation Internationale de la Vigne et du Vin, known by its initials OIV.
Based on the most current available figures, we consume more gallons of wine than we produce in the U.S. despite the fact that U.S. wineries exported a record $1.55 billion of wine in 2013, increasing both the volume of shipments and the price of American wines sold overseas.
Moreover, U.S. wineries shipped 48.4 million cases of wine to foreign markets in 2013, up 7.5 percent from 2012 and the highest since 2008, according to the Wine Institute. U.S. winery revenues increased 16.4 percent in 2013, reflecting growth in sales of higher-priced wines.
By the end of 2012, world wine consumption reached 2.663 billion 9-liter cases, according Vinexpo.
The bottom line is that 8,000 years since its humble beginnings, wine is a deliriously popular and economically significant component of the global and U.S. food chain.
Iconic author Robert Louis Stevenson (1850-1894) wrote “…wine is bottled poetry.” Without question, wine is a sensitive consumable and many factors affect and contribute to its quality and safety.
While not currently required to have a Hazard Analysis and Critical Control Points (HACCP) plan, wineries have been implementing HACCP with increasing regularity, says Randy Worobo, PhD, an associate professor in the Cornell University Department of Food Science. Dr. Worobo’s work includes developing HACCP plans for wineries.
“Even under the Food Safety Modernization Act (FSMA), wineries likely won’t be required to have a HACCP plan, but they will have to have a documented program in place to control biological, chemical and physical hazards,” Dr. Worobo points out.
There aren’t really any microbiological hazards associated with wine, Dr. Worobo says, since the alcohol protects it from foodborne pathogens.
In fact, the undisputed “father of microbiology” himself, Louis Pasteur (1822-1895) stated, "Wine can be considered with good reason as the most healthful and hygenic of all beverages."
That said, wine’s primary potential hazards are chemical and physical.
Glass is the key potential physical hazard and control of this hazard may be listed as a CCP in a winery HACCP plan or controlled by their prerequisite programs. “It’s absolutely essential that every winery have a glass control policy complete with a handling and breakage management program,” Dr. Worobo emphasizes.
Wine’s noteworthy chemical hazard is sulfur dioxide (SO2), and it might be advisable to include labeling for this hazard as a CCP, Dr. Worobo says.
First used in winemaking in 1487 as a preservative, SO2 currently serves an antimicrobial agent to inhibit yeast and bacteria, and also as an antioxidant to safeguard wine's fruit integrity and protect it against browning.
“Virtually all commercial wines have sulfites and a wine HACCP program should definitely have a sulfite management program,” Dr. Worobo advises. “To safeguard consumers who may be allergic to sulfites, 350 ppm is the maximum total allowed in the US 27 CFR 4.22(b)(1) for finished product, and wineries need a way to make sure they do not exceed that level.”
Normally, allergens in wine are controlled under a sanitation standard operating procedure (SSOP). Mycotoxins, particularly ochratoxin A, can be an issue in winemaking, depending on climatic conditions. “Thus, wineries may want to identify mycotoxins as a chemical hazard,” Dr. Worobo says. “If the risk for this hazard is great, a CCP to sort the grapes to remove any moldy grapes is advisable.”
Dr. Worobo mentions that another chemical hazard a winery might want to address is lysozyme, an enzyme that is extracted from the egg white of hens, which is an allergen and sometimes used as a clarifying agent. Lysozyme can be used in winemaking to prevent microbial spoilage by gram positive bacteria, delay malolactic fermentation (MLF) (the process in winemaking in which tart-tasting malic acid, naturally present in ‘grape must’ (i.e. young wine), is converted to softer-tasting lactic acid), or delay SO2 additions after MLF is complete. “It’s important that any wine containing lysozome be labeled as such,” Dr. Worobo says.
In general, HACCP plans are about the same for any type of alcoholic wines, but winemakers must evaluate the hazards for every type of wine they are making. “If you are using a fruit other than grapes, you may have other unique hazards,” Dr. Worobo explains. “Two examples are cherries and peaches whose pits contain cyanide. The pits will be filtered out during the winemaking process, but the cyanide will leach into the wine with the macerated fruit, which is then extracted as juice.”
The most important thing is for a winery to identify the most severe and likely hazards, and if a winemaker is calling a hazard a CCP, they must control and monitor it, Dr. Worobo emphasizes. “Don’t dilute the HACCP plan with too many CCPs, because then you will miss the most important points and end up with hazards in the finished product,” he advises. “If hazards can be prevented by strong prerequisite programs, it’s best to do that, rather than controlling them with CCPs.”
What about non-alcoholic wine?
“Non-alcoholic wine does have biological pathogens, so a HACCP plan to cover alcoholic wine may not sufficiently cover all of the issues of dealcoholized wines,” Dr. Worobo says. “Any winery making both alcoholic and non-alcoholic wines needs to have two separate HACCP plans. When making non-alcoholic wine, it is important to have processes in place to make sure pathogens don’t get into the product once the alcohol is removed. That involves documented good manufacturing practices, site-specific SSOPs for equipment and facilities, and employee training.”
Wine safety hinges on raw materials safety, packaged wine safety, and wine safety documentation, according to Glenn O’Dell, director of quality improvement for Constellation Brands, U.S., Inc., which operates 14 wineries in the U.S., plus others in Canada, Italy and New Zealand.
“Raw materials safety starts with grape grower documentation of compliance with pesticide regulations,” O’Dell begins. “For the very limited other ingredients used in our winemaking processes, a manufacturer’s certificate of analysis is required for fining agents and additives, including sulfites and allergens such as casein, albumin, and also enzymes.”
Selection of commercial pure yeast strains of Saccharomyces cerevisiae is standard practice for most winemakers, O’Dell adds, noting that technically speaking, pure cultures are raw materials not required to make wine.
“The time-honored method for winemaking was to crush the grapes and allow the naturally-occurring yeast present on the grape skins (and/or in the winery) to ferment the juice into wine,” O’Dell explains. “While at the initial stages of fermentation there are typically a large number of different organisms present, by the end of fermentation only a very few, (all non-pathogenic) organisms can survive in the low pH, high alcohol environment.”
The aforementioned organisms will be primarily yeast, O’Dell says, but there are will also likely be some bacteria present. Most are killed off very soon after fermentation starts by the alcohol. Some, like Acetobacter, can survive post-fermentation.
“There is a school of winemaking thought that says that these indigenous organisms create a desirable level of complexity that is not obtainable using pure cultures,” he relates. “Ironically, these wild fermentations are typically only encountered in high-priced wines.”
Relative to packaged wine safety, Constellation employs HACCP programs to keep glass fragments from bottles.
“All of our facilities have run hazard analyses on their processes, from receiving through distribution,” O’Dell mentions. “They have identified various low-risk hazards and implemented controls as appropriate to each facility and process. The only identified critical consumer hazard that is common to our HACCP plans is broken glass.
“Control comes from rinsing bottles to remove foreign materials just prior to filling, handling all broken glass encountered during bottling, following detailed and documented procedures, and performing random quality checks to assure glass conformance to purchasing requirements,” he explains.
Segregated storage and control of non-food grade materials are routine practices for Constellation.
Documentation is managed through lot controls; work orders; analysis of grapes, must wine and packaging materials; with paper trails linked by ERP (enterprise resource planning) software, O’Dell says.
“Understanding threats to wine quality, having strategies to control those threats, and maintaining systems to verify the threats are under control are key to any winery’s success,” O’Dell continues.
According to O’Dell, the five primary threats to wine quality are light, microbial spoilage, temperature fluctuations, unintended oxygen exposure, and time.
“Exposure to light can trigger undesirable chemical reaction[s] in some wines,” he says. “Some studies have shown that wines with the right precursors (thiols) can develop off aromas after even brief exposures to sunlight.”
Tetrapak, bag-in-box, and kegs provide positive light barriers, O’Dell points out. “Glass bottles rely on colors for light protection,” he relates. “Flint (clear) provides minimal protection. Various shades of green are better, depending on the color used. Amber is best, though it is not widely used.”
Pathogens may not impact wine safety, but microbes pose a threat to quality. “Microbial activity is required to make wine,” O’Dell says. “Wine without the action of microbes is juice. Some bacteria strains are intentionally encouraged or added to reduce acidity and add complexity. It can be said that wineries are stews of microbial activity. So these beneficial organisms, and a few other non-pathogens, become potential sources of spoilage later in the process.”
The five primary threats to wine quality are light, microbial spoilage, temperature fluctuations, unintended oxygen exposure, and time.
Constellation controls microbial spoilage by several means, including, but not limited to, inoculating with pure cultures; using non-chlorine gas sanitizing agents on tanks, grape and wine processing equipment, pipelines, hoses and fittings; appropriate use of SO2; hot water/steam sanitation of packaging lines following chemical cleaning in place; and membrane filtration inline to packaging.
“To scrutinize microbial control, we monitor CCPs, especially by evaluating sanitized surfaces using ATP [adenosine triphosphate]-sensitive swabs,” O’Dell mentions. “We also conduct sanitation audits of cellars and packaging facilities, and we plate for viable organisms in finished goods.”
While some oxygen exposure is a necessary part of wine development, too much oxygen exposure limits shelf life, O’Dell says. Closures, including various types of corks and screw caps, all offer benefits and downsides to maintaining seals on bottles, which impact oxygen exposure.
The optimum temperature for wine storage is generally 40 degrees to 60 degrees Fahrenheit. “Wine does develop with age,” O’Dell elaborates. “At lower temperatures it develops more slowly. At extremely low temperatures it can freeze. At higher but moderate temperatures, it ages more quickly. At very high temperatures, 90 degrees to 100 degrees Fahrenheit-plus, wine can cook quickly.”
Contrary to popular belief, all wines do not get better with age, O’Dell points out. “Old vintages are always rarer, but not always better,” he says. “Some wines do improve with age, for a while. Eventually, the combination of oxygen, temperature and time will limit the useful life of virtually all wine. The best we can do is monitor wine quality, assign an estimated shelf life to all lots and begin monitoring when lots in inventory are at risk of approaching their expected shelf life.”
Wine is regulated by the Alcohol and Tobacco Tax and Trade Bureau (TTB), under the U.S. Department of the Treasury.
“The goals of the TTB are to collect taxes and protect consumers,” says Brent Trela, PhD, an enology specialist who operates Alert Aesthetics, a private consulting firm that serves the international wine industry.
Specifically, TTB’s existing authority under the Federal Alcohol Administration Act’s [27 U.S.C. § 201 et seq.] Section 205 (e) is “to provide the consumer with adequate information as to the identity and quality of the products.”
To that end, TTB regulates labels, additives, processing methods, etc. (It is interesting to note, Dr. Trela says, that while TTB regulates the labeling of alcohol beverages, it is FDA's responsibility to evaluate the safety of ingredients added to alcohol beverages, but the TTB still regulates what ingredients are permitted to be added.)
“States can make more restrictive wine regulations,” Dr. Trela relates. “For example, California does not allow chaptalization, which is the process of adding sugar to unfermented grape must in order to increase the alcohol content after fermentation. The TTB does allow chaptalization under specific conditions.”
TTB also works to level the playing field to facilitate U.S. export, import, and domestic trade in alcohol, Dr. Trela adds. “Overseas, TTB serves the U.S. as a liaison among foreign governments, industry and the public in support of worldwide trade,” he explains.
Aside from TTB, the U.S. participates in the World Wine Trade Group (WWTG), an informal grouping of industry representatives from wine-producing countries around the world.
SO2 serves as an antimicrobial agent to inhibit yeast and bacteria, and also as an antioxidant to safeguard wine’s fruit integrity and protect it against browning.
The WWTG’s vision is “a successful, competitive and growing global wine industry, characterized by social responsibility, sustainability and focus on consumer interests, operating in a climate free of trade-distorting factors.”
As of now, FDA nutrition labeling is not mandatory for wine, and neither is allergen labeling.
“Even though beverage alcohol is not within the jurisdiction of the FDA, TTB, in cooperation with the FDA, issues its own allergen labeling requirements,” Dr. Trela says. “The voluntary interim rules require specific information and wording to be included if a producer, bottler, or importer of any alcoholic beverage discloses information. Any allergen declaration must state ‘Contains’ followed by the common name for the major food allergen.”
The TTB published an interim rule, T.D. TTB-53, 71 FR 42260, effective on July 26, 2006, which sets forth standards for optional allergen labeling statements. “This is still the official statement from the TTB,” Dr. Trela points out. “There has been no date offered for implementation, other than indications that ultimately there will be mandatory allergen disclosure requirements in the U.S. for all alcoholic beverages.”
FSMA will affect wine production, Dr. Trela notes. Actually, it already has. During fiscal years 2009-2012, about 393 FSMA winery inspections were conducted nationwide.
“While the FDA has always had inspection authority over wineries, many of the 2011 FSMA provisions do not apply to wineries,” Dr. Trela says. “However, there are instances where they may be invoked and compliance with the entire Act is required through Section 116: a) distribute an unpackaged or repackaged (e.g. potentially exposed to direct human contact), non-alcohol food item; or b) sell prepackaged food in an amount greater than 5 percent of the overall facility sales. The FDA sought public comment on the rules and potential impacts of the FSMA on wineries that concluded in November 2013. Further regulations or changes to the regulations are expected to follow.”
FSMA states that all food facilities must be inspected within seven years and at least once every five years after that.
“The FDA may contract state agencies to conduct winery inspections,” Dr. Trela says. “The FSMA directs the FDA, under the federal Bioterrorism Act, to inspect every registered food facility, including wineries, in the U.S. by 2018. Due to the recognized relatively low food safety risk of wines, the FDA may scrutinize wineries less than most other food facilities. Subsequent inspection frequency may likely be based on risk assessments and facility compliance history.”
Leake is a food safety consultant, auditor, and award-winning journalist based in Wilmington, N.C. Reach her at LLLeake@aol.com.