Each puerh tea cake has its age.There are a date tag on puerh tea cakes.For cooked puerh, the taste can be good after two years of natural post-fermentation; While for raw puerh,it takes at least five years of natural post-fermentation before it get good taste.According to puerh's theory,the good ages of cooked puerh tea cakes range from two to twenty years old;While for raw puerh tea cakes,the good ages range from five to thirty years old. During those good ages, the age is older, the quality and taste is better.But this theory is inaccurate,because we found that the quality and taste may go bad if it is too old,though its age are still within those good ages,so you donot need pursue too old puerh tea.