(Adding too much acid to the concentrate or maintaining a pH below 4 can evolve the chlorine dioxide gas at an accelerated rate especially when aerated). In one method of activation, citric, lactic, or phosphoric acid is added to drop the pH of the water to between pH 4.5-5. Five molecules of the sodium chlorite use four molecules of acid to make four molecules of the chlorine dioxide gas and some leftover salt and water. This method works well for small volumes of water or with soft water. One sanitizer was an acidified solution of dilute sodium chlorite at pH 2.7; the other sanitizer was dilute chlorine dioxide (about 15 ppm) in tap water. Chlorine dioxide cannot be stored for too long, because it slowly dissociates into chlorine and oxygen.It is rarely stored as a gas, because it is explosive under pressure. Post-rinse sanitize. Remember, there is no residual. The solution is normally either pumped through sprayballs (like CIP), or in the case of open fermenters, sprayed with a pump-up sprayer just before the beer is pumped over to the fermenter being sanitized. The best way to store chlorine dioxide is as a liquid at 4 ºC. Keeping the Workforce Safe During the COVID-19 Pandemic. Overusing iodophor serves only to flavor beer and does not offer any additional microbiocidal effect. Stay away from the glug method when dispensing sanitizers. A post-rinse sanitizer which is not iodine based has started gaining acceptance with craft brewers. For brewers to try sanitizing with chlorine dioxide, a small pilot batch or system should be tested. For best results, use the cold tap water and keep the temperature of the solution below 80 degrees F. Do not reuse the solution. Homebrewers are familiar with sodium hypochlorite (NaOCl), 5.25%. At this state it is fairly stable. • Solutions used for sanitizing equipment shall not exceed 200 parts per million (ppm) available chlorine. A traditional procedure for cleaning and sanitizing utilizes the following steps:
 1. Unless you have a good method of determining chlorine dioxide levels in the water, it is best to start with a fresh solution for each application. As shown in Table 1, about one tablespoon (1/2 fluid ounce, 15 ml) of typical chlorine bleach per gallon of water is the maximum that should be used for sanitizing … In other words, you will still get an effective kill at an active level of 50-100 ppm ClO2 while maintaining a minimal or non-existent flavor profile. If the sanitizing solution begins as a sodium chlorite solution, 8.3% by weight, and the known reaction efficiency is 97%, then the yield will be 6% chlorine dioxide. Learn more about our peracetic acid sanitzer: Birk-Ox ➔. While the majority of brewers do not over use iodophor, occasionally it is noticeable in finished beer. 3. Proper measures need to be taken not to overuse any sanitizer. Brewers know that carbon dioxide is more stable at colder temperatures (known as Henry’s law). Federal exposure limits of chlorine dioxide are published in the MSDS. How can chlorine dioxide be stored? As little as 1-2 ppm active hypochlorite is detectable in drinking water. Conversely, chlorine dioxide is ideal for sanitizing after the cleaner has been rinsed. The 8-h time weighted average for chlorine dioxide is 0.1 ppm. Protecting the food chain for over three generations. Rinse with phosphoric acid to neutralize the caustic and remove beerstone (calcium oxalate). Because fibers from the boxes can be electrostatically deposited inside the bottle, many breweries rinse the bottles just prior to being filled. Once a system for cleaning and sanitizing is established that actually works and a quality beer is produced, it is tough for change to occur. In his book, The Complete Joy of Homebrewing, Charlie Papazian recommends using 2 ounces of bleach per 5 gallons of water to clean and sanitize fermenters and bottles. The bottles simply need to be inverted to drain the excess sanitizer prior to filling. Unlike iodophor, however, the amount used is typically not as critical both in terms of microbial reduction and flavoring beer. © 2020 Birko. By using iodophor and/or chlorine dioxide properly, the brewer can prevent these organisms from gaining a foothold in the brewery and maximize the shelf life of their beers. In the case of sodium hypochlorite bleach, they are correct. Brewers frequently struggle with the best way to ensure microbial free equipment.