How lond does a blackberry needs to be in the vine after it is black?

Because i picked abt 6 blackberrys and they all are black and they taste so sour i wanna know how long does it need to be in the vine after its black thanks to all answerers.

How lond does a blackberry needs to be in the vine after it is black?
Once they turn black the are ready for picking;

They usually need a little sugar anyway, I*ve had mine for years and they do taste a little sour.
Reply:Where abouts did you pick them from. The biggest--the blackest and the sweetest are always on the top most of bushes.
Reply:A ripe blackberry is deep black with a plump, full feel.
Reply:A ripe blackberry is deep dull black with a plump, full feel %26amp; a rich aroma. As they turn black, they begin to soften and become sweet. It will pull free easily from the plant... falling to your hand with a slight touch. If the berry is red or purple, it's not ripe yet.

http://www.wildmanstevebrill.com/Plants....

http://www.pickyourown.org/blackberries....



If they're sour %26amp; they're already dark dull black %26amp; fall off easily from the vine ...it's most likely either a wild type of blackberry or they didn't get enough water when developing.
Reply:A blackberry is ripe and ready if when you tug on it to pick it, it practically falls off. In other words, you do not have to pull hard on it to pick it.