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Ozone has been shown to be an effective way to kill ''Brettanomyces'' that is buried in the wood of oak barrels (it has been found to burrow as deeply as 8 mm into oak barrels), but the ozone must be applied for an adequate time to allow for the ozone to diffuse into the oak. The amount of time needed to completely kill ''Brettanomyces'' living within barrels with ozone is not known, but it was found that 30 minutes of exposure to 40 mg/m<sup>3</sup> ozone concentration was not enough time and the presence of organic material interferes with the ozone's ability to kill <ref>[https://www.researchgate.net/profile/Raffaele_Guzzon/publication/225890726_Survey_of_the_yeast_population_inside_wine_barrels_and_the_effects_of_certain_techniques_in_preventing_microbiological_spoilage/links/5472f6170cf2d67fc035d45f.pdf Survey of the yeast population inside wine barrels and the effects of certain techniques in preventing microbiological spoilage. Guzzon, Raffaele & Widmann, Giacomo & Malacarne, Mario & Nardin, Tiziana & Nicolini, Giorgio & Larcher, Roberto. 2011.]</ref>. The concentration of ozone is known to be a more important killing factor than time, therefore some recommend filling the barrel with liquid ozone, or rinsing with hot water first to open the pores of the wood and then rinsing with ozone liquid <ref>[https://www.facebook.com/groups/MilkTheFunk/permalink/1860978937263645/?comment_id=1861100817251457&comment_tracking=%7B%22tn%22%3A%22R5%22%7D Nate Ferguson of Escarpment Labs. Milk The Funk Facebook thread about using ozone to sanitize barrels. 10/24/2017.]</ref><ref>[https://www.winesandvines.com/features/article/109491/Barrel-Washing-Protocols Wines & Vines website. "Barrel-Washing Protocols". Jan 2013. retrieved 10/24/2017.]</ref>.
Other non-thermal methods of pasteurizing barrels have been explored. Microwave treatment at 3000 W for 3 minutes of barrels filled with water reduced populations by 35% in French oak barrels and 67% in American oak barrels up to the 8 mm depth in which ''Brettanomyces'' can survive within the wood of oak barrels. High power ultrasonics (17 W/L for 3 minutes) applied to barrels filled with 60°C water kills all ''Brettanomyces'' up to 4 mm within the oak, but has limited penetration of the wood passed 4 mm <ref name="Cartwright_2018" />. The use of sulfur dioxide (SO<sub>2</sub>) has been shown to inhibit ''Brettanomyces'' and other microbes, however, ''Brettanomyces'' cells that are exposed to sulfur dioxide can enter a state known as "viable but nonculturable" (VBNC) meaning that they cannot complete cell division (grow) but can still maintain a small amount of metabolism, and can be revived when the sulfur dioxide is no longer in their environment. Therefore, sulfur dioxide is not an effective way to completely sanitize oak barrels (although it has been used successfully to store non-infected barrels). See [[Quality_Assurance#VBNC_In_Yeast|VBNC in Yeast]] for more information.
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