a zest or zest

[Bennevis]

I wonder if we need an indefinite article in front of the word "zest" in a sentence of this kind:

It will certainly add zest to your relationship.

[5jj]

No.

[Bennevis]

Merci!

[vil]

Learn how to add zest to your food.
It is easy to add zest and zing to a living room.


...give zest to...


but

Dog trained by prisoner gives teen a zest for life

I do not, of course, mean that there are not battles, conspiracies, tumults, factions, and all those other phenomena which are supposed to make History interesting; nor would I deny that the strange mixture of the problems of life and the problems of Mathematics, continually inducing conjecture and giving the opportunity of immediate verification, imparts to our existence a zest which you in Spaceland can hardly comprehend.

V.