About my experiment. " longest lasting flavour "

I have always been interested in which gum brand is the best to buy. I thought of 4 well known brand which are 5Gum, P.K, Juicy Fruit and Extra that are going to compete with each other to find out which brand has the longest lasting flavour. My plan on my experiment is to record the time of how long each piece of gum brand loses its flavour. But to make this experiment fair i plan to cut off pieces of the gum or add on pieces of the gum to make it even.