When you make flavored syrup for snow cones or other shaved ice deserts and you want it to remain fresh for up to 6 months without refrigeration, you absolutely must preserve it. Citric Acid and Sodium Benzoate can be combined to produce a very effective FDA approved Preservative. However, one without the other will not give long term preservation. But when they are combined and used in the proper quantities, snow cone and shaved ice syrup will remain fresh for up 6 months. Citric Acid is actually produced naturally in citrus fruit but it is not very effective when used alone and neither is Sodium Benzoate when used alone. Citric acid produces an acidic environment which is required in order for the sodium benzoate to become active. Snow Cone Syrup preserved with Citric Acid and Sodium Benzoate maintains it's shelf life even after it has been opened. Some of our customers tell us that the syrup will remain fresh for a year or more if kept refrigerated. However, Ralph's SnoBall Supply has not confirmed these reports. This method of preservation works especially well for snow cone syrup made with 100% pure cane sugar and Snow Cone Flavor concentrate. Just remember that the citric acid and the sodium benzoate should be stirred into the syrup separately. If you stir them in at the same time a white mealy crystallization will occur and the effectiveness of the preservative will be reduced or it might not work at all. Use 1/4 ounce of citric acid and 1 ounces of sodium benzoate to preserve 1 gallon of snow cone or shaved ice syrup. That is a 1 to 4 ratio (1 part citric acid to 4 parts sodium benzoate). Once the syrup has been preserved it should not be exposed to direct sunlight or strong bright light for long periods of time. Exposure to strong light for extended periods of time will cause the color of the syrup to fade and the shelf life will also be reduced. Without preservatives, the syrup has a 1 to 2 week shelf life. If you plan to use your syrup within this time period there is no need to to add preservatives. However, it is better to be safe than sorry and that is why we recommend using a preservative. Snow cones are delicious but like anything else we consume, if it goes bad it will be a horrible taste experience.