Sodium bisulfite, or NaHSO3, is a chemical sanitizer, preservative and water dechlorinator. For these applications, sodium bisulfite is interchangeable with another bisulfite, sodium metabisulfite. Sodium bisulfite is available in a granulated form that resembles table salt. Combining sodium bisulfite with water produces sulfur dioxide gas, which kills unwanted microorganisms. Sodium bisulfite also prevents oxidation and as so, acts as a preservative.
Wine Making
Sodium bisulfite is available in wine-making stores to sterilize and preserve homemade wine. A small amount added to the pressed juice will kill any alcohol-resistant mold that is on the fruit. The amount you add varies depending on the presence of any over-ripe or possibly moldy fruit. After you add the sodium bisulfite, the juice should sit uncovered for 24 hours so that the sulfur dioxide gas can escape. Once the wine is ready to be bottled, you should add more sodium bisulfite to act as an antioxidant to preserve color and flavor. In higher concentrations, you can use sodium bisulfite as a sanitizer for wine bottles, corks, hoses and other equipment.
Fruit Preservative
You can preserve canned or dried fruit using sodium bisulfite in a process called "sulfating." This process not only preserves the fruit, but also stops unwanted browning and slows the loss of vitamins A and C. You should soak fresh fruit in a solution of sodium bisulfite for 5 to 15 minutes, depending on the size and quality of the fruit. After soaking, give the fruit a light rinse, and then can or dry it in a well-ventilated area. Manufactured dried fruit typically uses bisulfite as a preservative as well.
Dechlorination
Small water treatment plants use sodium bisulfite to remove chlorine from the waste-water discharged back into lakes and rivers. Lingering chlorine is not only toxic to aquatic life, but it forms toxic chemicals when exposed to organic materials in environmental water. Mixing the water with sodium bisulfite releases sulfite ions. These bind to the free chlorine, removing it from the water. If too much sodium bisulfite is used, the excess sulfite reacts with oxygen in the water producing sulfates. The resulting waste-water is not healthy for the environment as it is slightly acidic and has low oxygen levels. For this reason, the larger treatment plants use the more easily controlled sulfur dioxide.
Bisulfite Sensitivity
Medications, such as dental anesthetics or eye drops, may contain sodium bisulfite as an antioxidant preservative. Along with the related chemical sodium metabisulfite, sodium bisulfite is recognized as potentially causing allergic-type reactions. Sensitivity to these sulfites is more likely to occur in individuals with asthma, according to Drugs.com. These allergic-type symptoms can be severe enough to produce a life-threatening anaphylactic reaction. Allergy testing is available from your doctor if you suspect you may have sulfite allergies.
Member Comments