Question

these grapes taste sour change into passive voice ​

Answer 1

sour is the taste of grapes .

Answer 2

Since the word 'taste' is an intransitive verb, it cannot be changed into passive voice.

Since there is nothing being done by anyone, we cannot add 'by' in any way, which is a common addition in most passive voice sentences.

However, we can change it in the following ways:

Taste of these grapes is sour

These grapes are sour when they are tasted"