Is aged pu-erh always of premium quality?

The answer is not necessarily. I have always assimilated this to wines. A good premium wine as we know can have aging potential due to the bio-chemical changes that naturally occur. A low quality wine can only turn into vinegar.

The sample principle applies to Pu-erh tea. Like all classes of Chinese teas, Pu-erh tea has many quality grade depending the plantation where the leaves are harvested, tea making skills of the processors and storage etc.

The changes of a premium Pu-erh tea with age include:

1. Reduction of the rough texture caused by the raw and big new leaves – from rough to mellowing
2. Yielding a unique pu-erh aroma and flavour, described as earthy and woody, yet not muddy with a trace of fruit or nut flavour depending on the variety
3. Tea brew colour gradually turn darker into bright amber

A few hints:

1. A raw pu-erh has better aging value than a ripened pu-erh
2. Compressed form of Pu-erh tea, should it be cake, brick or Tuo-Cha, facilitate the post-fermentation
3. A raw pu-erh will not turn into a ripened Pu-erh with time (misconception)
4. There is no maximum time for aging, but it is generally believed a tea should be consumed within the 20-30 years of its production