Snow cone concentrates have a 2 year shelf life and do not require refrigeration. Opening the bottle of concentrate does not shorten the shelf life. Using more concentrate than the reccomended amount will not make the snow cone syrup taste better. In fact, it could have the opposite affect. Shake the concentrate well before using and use 4 ounces per gallon of simple syrup. 32 Gallons of snow cone syrup can be made from 1 gallon of concentrate. Store away from direct bright light in order to preserve the color and maximize shelf life. 

See the "frequently asked questions page" for mixing instruction