The proof is in the pudding - Tradução em português

Hi there,

the proof of the pudding (is in the eating) = you can only judge the quality of something by trying it for yourself
(Macmillan)

Mais sobre a expressão:

The entire phrase is "the proof of the pudding is in the eating," meaning that the true value or quality of a thing can only be judged when it is put to use. ("Proof" in this context means "the act of testing," rather than our more common "conclusive evidence" sense.) "The proof of the pudding is in the eating" dates back to around 1600, and is more often heard in the United Kingdom than the U.S., probably because puddings of various kinds occupy a more prominent place on the dinner table there.
fonte: http://www.word-detective.com/081100.html#proofpudding

é possível relacionar com o nosso "só acredito vendo" ?