De or het flesrijping?

The correct Dutch article is:

de flesrijping

Rule Words ending in -ing: almost always de. See the rule

How to use flesrijping

the flesrijpingde flesrijping
this flesrijpingdeze flesrijping
that flesrijpingdie flesrijping
our flesrijpingonze flesrijping
your flesrijpingjouw flesrijping
every flesrijpingelke flesrijping
which flesrijping?welke flesrijping?
a big flesrijping / the big flesrijpingeen grote flesrijping, de grote flesrijping