I have been recently trying to solve this problem. I noticed that in the few varieties that I grow, a pom reaches its ideal picking time, after which the acidity starts to fade out is when the very first drying marks around the bottom of the fruit appear.
For example, this one was excellent:
This in the other hand, although a different variety but this was mostly sweet, and even dry’ish berries.
They were both esthetically excellent.
