maturation

matu|ra|tion /m'ætjʊr'eɪʃən/
1 [N-UNCOUNT]
The maturation of something such as wine or cheese is the process of its being left for a time to become mature. (FORMAL)
The period of maturation is determined by the cellar master.
2 [N-UNCOUNT]
The maturation of a young person's body is the process of it becoming like an adult's. (FORMAL)