Chapter 14

Winery Cleaning and Sanitizing

Winery Sanitizing Agents

Once deposits and debris are removed and surfaces are visibly clean, the equipment can then be sanitized. Sanitizing agents (often called disinfectants) are used to reduce the number of microorganisms to acceptable levels in the winery. Sanitizing may be accomplished by physical methods or through the use chemical sanitizers. Physical methods include the use of either steam or hot water to kill bacteria.

Hot Water and Steam

Ideally, hot water used for sanitation should be at least 82 degrees C (180°F) at discharge, circulated or held for a minimum of 10 to 15 minutes. If you cannot maintain the higher temperature, the time should be increased (i.e., 20-25 minutes) with a minimum temperature of 179 degrees C (175°F). It is critical that time and temperature be monitored carefully to ensure reliable results.

Quaternary Ammonium

Quaternary ammonium compounds, commonly referred to as QUATS or QACs, are used extensively in wineries because of their stability and non-corrosiveness. They have rapid bactericidal action at very low concentrations but selective biocidal activity. Gram-positive bacteria (Oenococcus, Pediococcus, and Lactobacillus) are most sensitive, whereas Gram-negative bacteria (Acetobacter and Gluconobacter) are less so.

Peroxyacetic Acid

Peroxyacetic acid (PAA) is a sanitizing agent widely used in the brewing industries and increasingly in the wine industry for its ability to efficiently kill microbes and sanitize surfaces on contact. Peroxyacetic acid is gaining popularity as a sanitizing agent in the wine industry for its broad microbicidal capacity, and rapid, on-contact efficacy under a range of conditions.

Ozone

Ozone is one of the most potent sanitizers available and is finding increased use in the wine industry. Ozone is effective against bacteria, fungi, and viruses. Unlike chemical sanitizers, ozone oxidation leaves no harmful or foul byproducts and residue, only oxygen. Because it's highly reactive and unstable, ozone doesn't persist - any ozone not instantly consumed by contact oxidation of organics quickly reverts to oxygen. This makes ozone perfect as a final, no-rinse sanitizer. With no persistence, ozone requires no special disposal system.

Chlorine Dioxide

Chlorine dioxide's properties make it an ideal choice for most winery operations. Chlorine dioxide is a strong oxidizing agent. Chlorine dioxide possesses broad spectrum antimicrobial capabilities. It is effective against a variety of wine spoilage organisms, including bacteria, yeast, and mold. Chlorine dioxide can be applied in several different areas of the winery, including CIP sanitizing of tanks and lines, water treatment, and environmental sanitizing (e.g., floors, walls).

Iodophors

Iodophors are considered to be broad spectrum sanitizer with demonstrated effectiveness against a variety of bacteria, yeasts, and molds. Iodophors are iodinecontaining formulations are usually composed of elemental iodine, a surfactant, and an acid such as phosphoric acid. Though not as effective as other sanitizing agents, its major advantage is that it evaporates directly from solution to gas when used in proper proportions, and hence leaves no residues and, as some manufacturers suggest, requires no rinsing.

Acidulated Sulfur Dioxide

Acidulated sulfur dioxide may be used as an effective sanitizing agent especially for hoses. Because the antimicrobial activity of sulfur dioxide is pH dependent, the sanitizing agent (100mg/L sulfur dioxide or 200mg/L potassium metabisulfite) is usually made up in acidulated solution by inclusion of 3 g/L citric acid.

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