The taste of pudding can have several different tastes since there are different flavors of pudding.
Pudding has many flavors including Tapioca Pudding, Vanilla Pudding, Chocolate Pudding etc.
So the pudding you make or eat will taste either like Vanilla, Chocolate or Tapioca or any other types of pudding.
If you're referring to a saying of the taste of pudding it means the taste of the pudding is in the Eating.
Every experience that comes your way has its own process of journey and destination
Just like the saying of the proof is in the pudding.
And the saying the proof is in the pudding means to be able to fully judge how effective something is you need to use it for its intended purpose.