“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.”
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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.