EXCERPTS FROM VARIOUS ARTICLES ON STEAM, WATER AND OZONE

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1 EXCERPTS FROM VARIOUS ARTICLES ON STEAM, WATER AND OZONE Using hot water to "sanitize" bottling lines, barrels and tanks is rapidly becoming too much water down the drain. It is time to consider an environmental and economic alternative that not only raises temperature to "sterilize" but uses virtually no water. Looking at the bottom line, wineries are increasingly turning to steam. Aside from producing minimal wastewater, generating steam is quick, saves money and is considerably more effective than a typical 180-degree water "bath." Raising the "temperature bar" to 212 F elevates the "kill ratio" or LD (Lethal Dose) on molds and bacteria beyond sanitary to sterile. For years, this is why steam has been the standard for the medical and pharmaceutical industries. WineBusinessMonthly- How Steam Works It is important to remember that you do not create energy. Energy already exists and is merely transferred. The merits of steam are based on its ability to quickly transfer high levels of temperature. It should not be viewed as anything more than an efficient vehicle that stores, then transfers, energy. When discussing water, we usually think of two factors: latent heat of fusion, which turns solid ice into a liquid, and latent heat of vaporization, which turns that liquid into a gas. Obviously, energy has to be absorbed to move molecules apart (ice to liquid). To change liquid into a gas and overcome the strong attraction between water molecules requires substantially more energy. There is also "wet steam," what you see when looking at a pot of boiling water. Then there is "dry-saturated" steam, meaning that 98 percent of the total water "droplets" has been fully converted into a gas. This is the form of steam that should be used in the winery and by far represents the most efficient form of transferable heat. Transference of heat, when using only hot water, is done via absorption. The object must be subjected to a constant flow or "bath." It is a less efficient process requiring longer periods of time and considerable amounts of water. Latent heat of vaporization, or steam, transfers its entire amount of stored energy (212 F of temperature) instantly upon contact to whatever surface it touches. Anyone who has been subjected to "scalding" steam will appreciate the concept. The time to take a surface (stainless tanks, monoblocks) to sterile levels of temperature is dramatically reduced, and the amount of water consumed is totally insignificant. Hence the practicality of steam: time savings and reduced wastewater. Applications for steam in the winery are as varied as there are places for bacteria and mold to live. Many winemakers now use steam to (1) clean and hydrate barrels, (2) remove tartrates and sanitize tanks, (3) clean equipment and walls and (4) the most familiar, sterilize the bottling line. -WineBusiness.Com-

2 Perspectives on Temperature Many winemakers are of the mind that hot-washing a barrel will sterilize it, which is not true. The barrel is basically a sponge, a once living piece of cellulose that is now dead, porous, permeable and easily attacked by bugs. Brett loves barrels and, given the right conditions, can hide deep inside the wood. Unfortunately, wood is a good insulator and a poor heat conductor. While heat will kill bugs, many winemakers confuse sanitized with sterilized. Some argue that 180 degrees will kill Brett, but, again, heat penetration is severely limited in oak. And if you do use 180-degree water, you generally have to hold that for up to a half an hour to get results. Sterilization, on the other hand, is easily achieved in stainless steel tanks because they hold temperatures of 212 degrees. Temperatures that high are undesirable in barrels because they might cause the development of off-flavors in the wine. An empty barrel can retain up to five liters of wine in the wood, which will be subjected to these high temperatures. Ecklin said, "Temperature is important in tartrate removal, and we use around 140- degree water. While 180 degrees might work better, we also don't want to scald our people." Finally, steam is another option. Because it is a gas, it can penetrate pores more effectively than water. And if a barrel is bunged immediately, as the steam cools it will begin to create a vacuum. By pulling a vacuum it is believed that residual wine can be extracted from the wood. Lastly, and very important, steam requires only a fraction of the water and energy used for hot-water flushing. Since most barrel washers require add-on pressure and heating generators, it might be a good idea to research heaters that can be regulated, taking temperatures to180 degrees and even beyond to actually produce steam. The cost differential is not much. Also, most agree that a barrel will be neutral (lose its ability to impart oak flavors) in three years. Having steam might become a benefit for long-term barrel maintenance, especially with barrels that will be used for years for mere wine storage. Steam can also be utilized elsewhere throughout the winery, especially on the bottling line.

3 Barrel Cleaning Nooks and crannies are also the favorite places for bacteria to hide in barrels, but being in gaseous form, steam will effectively penetrate the cellulous structure of the wood. Also with high temperature, tartrate removal is considerably easier, taking far less time and using virtually no water. Some winemakers may question the use of steam in their expensive European oak, thinking it could possibly volatilize flavors. For others it isn't an issue. Fritz Meier, a winemaker at Kendall-Jackson and formerly at Husch Vineyards in Philo, California (35,000 cases), said he used steam for "peace of mind...i was trained in Germany, and everyone used steam for everything in the winery. Water and energy costs are just too expensive." Robert Morris, operations director at the Copain Custom Crush facility in Santa Rosa, California (75,000 cases), also promotes steam. "We are a premium winery with many customers, and everyone has a primary goal of unfiltered wine. It is critical that we maintain absolute cellar health. Primarily, we use steam to clean and maintain our barrels, and then use Select Mobile Bottlers for bottling," he said. "I received my classic training in Bordeaux, France, and I continue to steam my barrels," said Chris Phelps at Swanson Vineyards in Rutherford, California. "We use low pressure of 10 to 12 PSI for about three to five minutes, then bung the barrel. As the steam cools and returns to liquid, it pulls a vacuum and can actually help extract old wine from the wood. It will also help remove bitter tannins and re-hydrates all at the same time." All winemakers lauded the ability to hydrate barrels in storage. "Barrel maintenance is where steam really shines," said Meier. "It can really help tighten up a barrel, especially around the head," said Phelps of Swanson. And at Copain, Morris said, "We can actually revive a barrel and continue to use it years longer than without steam." Another plus is that steam enables the winemaker to check the integrity of the barrels. Steam will quickly penetrate and reveal any leaks that may have developed. As mentioned, after you steam and insert a bung, a vacuum develops. If the bung is hard to remove, it means absolute leak-proof integrity in the barrel. Caution is advised because the process is so effective it can actually collapse a head. Caution is advised when cleaning barrels because it is the one time when workers are directly exposed to the scalding effects of steam. Bottling line and tank cleaning is a matter of attaching the equipment and walking away. The only danger is touching the stainless before it has a chance to cool. Barrel cleaning, however, is hands-on, and cellar workers must be educated in the inherent danger of direct contact. A special wand must be inserted into each barrel. It is advised, therefore, that workers wear protective gloves rated for high temperatures. Wine Business Monthly-

4 Water Usage Of all the charts in this survey, Charts 4 and 5, revealing water usage and reclamation, are possibly the most telling of the current state of affairs in our industry. Winemakers may argue technique and results, but Chart 4 shows that regardless of size, small and large wineries march in unison, be it three, four or five gallons per barrel and surprisingly all the way to seven or more. The only conspicuous drop is at six gallons and probably for no reason. If anything, the precipitous drop at six gallons might be less a reflection of a consumption-benefit ratio as the fact that some responding wineries aren't really measuring the amount of water used during barrel washing. Unless the winery is automated to some level in barrel washing and incorporates a timing mechanism, the standard procedure may be to turn on the washer and rinse until "clean." The problem is determining "clean." Looking through a bung hole of a 60-gallon barrel with a flashlight, not to mention the constricted edges of the barrel head, may beg your ability to determine clean. And while water may eventually flow clear, have you adequately removed tartrates? To further the argument, Chart 5 shows that 87 percent of small wineries and 66 percent of large ones do not have a system to reclaim water. Some are more proactive than others. RoxyAnn Winery in Medford, Oregon (15,000 cases) has decided to address the issue. "In the past we used our orchards for reclamation," said winemaker Gus Janeway, "but we already have plans for a new wastewater system for more efficient usage. It will include metering so we can accurately monitor our output." "With the California Central Valley water agency closely monitoring, we have to be careful about water use," said Mike Robustelli, winemaker at McManis Family Vineyards in Ripon, California (275,000 cases). "We have gone so far as to install trigger nozzles on all our hoses. Unless you squeeze the trigger or are in attendance, the water does not flow." Vino Noceto Winery in the Sierra Foothills in Plymouth, California (10,000 cases) has an even more ominous issue. The county receiving station that accepts septic refuse will not take winery water because of ph and particulate issues. The water is removed to a special treatment center. "The water control board is so strict we must collect and then have a septic service remove our wastewater. It costs me 37 cents per gallon," said winery owner Jim Gullett.

5 Ozone and Steam Possible solutions to excessive water usage can be found in alternatives, such as ozone and steam. The overall effectiveness of ozone is still a matter of debate, but it is generally considered as one more bullet in the battle against Brett. The survey of ozone usage in Chart 6 shows that ozone is still not overly popular with smaller wineries, with only 40 percent using it, compared to 74 percent of medium to large wineries. Any number of reasons may be a factor, including OSHA defining ozone as hazardous and requiring proper training. OSHA also requires wineries to have clean water without any organics (iron or manganese). These issues may not be as much a concern for larger wineries as for smaller ones. In addition, the cost of entry at around $11,000 may prove prohibitive for smaller operations. Finally, the last element in relation to cleaning a barrel is steam. While the advantages of steam cleaning are numerous, Chart 7 reveals that few people are currently using the technology. Over time, especially with water concerns becoming paramount, it will be interesting to see if we witness an emerging trend in the future. Not only does steam clean a barrel while using virtually no water, it is considered highly effective and efficient. Also on the plus side is that a standard 30 Kw unit for a small winery is only about $5,000. Proper training is important due to the inherent high temperatures, but not as critical as it is with ozone. It is interesting to note that of all the wineries using steam, 21 percent of the total are small while only 7 percent are large. "We use lots of steam and ozone in Australia," said Mike Zitzlaff, winemaker at CrushPad, Inc., a custom facility. "Over there we have had many years of drought and have had to work to conserve water." Ozone No discussion of barrel hygiene would be complete without addressing ozone. Ozone is a highly unstable, three-atom oxygen molecule (O3). It is highly reactive, meaning it will immediately release the third atom upon contact with any organic material, thereby "oxidizing that material." It has been introduced into wineries in the last few years in either a gaseous form or dissolved in water, and helps sanitize (not sterilize) by eliminating yeasts, molds and bacteria. While debate still continues as to overall effectiveness, there are other issues that should concern the winemaker. First it is recognized by OSHA as an irritant and is listed as hazardous to workers. (Ecklin advised using a hand-held detection unit to monitor the work area.) Secondly, for best results it requires a clean water source without organics, irons and manganese, which is difficult for wineries on wells. Third, because it is so unstable, it will "gas off" easily and can quickly deteriorate the natural rubber-based gaskets, seals and hoses of any nearby winery equipment. Fourth, it is an ineffective cleaner, so a barrel must be thoroughly cleaned beforehand. Finally, unless it is in gaseous form it might not penetrate completely into problem areas of the porous wood structure of the barrel.

6 "For us, it is just another level of insurance," said Eric Henn at Vine Cliff Winery in Napa. "It is not intended to kill everything but to simply hold down populations." Dan Cederquist, consulting winemaker for Sonoma Wine Company, Hook and Ladder and Balletto wineries in Santa Rosa, California, agrees. "Ozone is just another arrow in your quiver." He also warned of potential water issues and to "test your water first. Not everyone can use ozone." Dr. Randy Worobro of Cornell's agricultural experimentation station, professor of food microbiology, science and technology, questions the effectiveness of ozone. He suggested that restaurants are a good analogy as they are concerned with hygiene and food processing. We called four restaurant supply houses in Sonoma County and asked if ozone is a part of restaurant cleaning. Four out of four said no. The cost of using ozone is prohibitive for most small wineries. A typical ozone generator runs about $11,000 and also needs to be integrated into the wash cycle. Unfortunately, as yet another step in the cleaning process, the generation and use of ozone translates directly into increased water and energy usage. Conclusion As one of the most expensive operations in the winery and as concerns about water conservation mount, barrel washing efficiency is increasingly more important to winemakers. While we have addressed a wide range of options and perspectives on barrel washing, conservation might affect your decision more than any other. And even if it doesn't, understand that using copious amounts of hot water might put you on the radar of any number of local, state and federal agencies interested in maintaining water quality and allocating water rights. Effect of Barrique Sanitation Procedures. Malfeito-Ferreira, 2004 Barrel sanitation experiment Cold rinse, then hot water rinse 3x 70 C Same as above plus SO2 1 month (200 ppm ph3) Cold rinse, fill with 90 C water 15 min Cold rinse, 70 C rinse, steam low pressure 10 min Most effective treatment Brett / Dekkera was found 8 mm deep in staves. Barrels cannot be sterilized with SO2, rinsing, or ozone. Isolate Brett+ barrels.

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