Concord Grapes

We planted Concord Grapes 3 years ago and this is the first year we have had grapes.  Grapes usually have one season that they establish themselves and then produce the next.  Why did it take us 3 seasons?  We had an early frost last year that killed all the growth and the plant had to grow back from the roots.  We now know that grapes are very sensitive and need a lot of tender care if you want any grapes.  Last fall we mulched heavily around the vine and coved it in the spring if there was any chance of frost.  We only have 6 clumps of grapes this year but we are happy to just have grapes.  I don’t mind.  I need a juicer first so I can make jelly and juice.  This gives me at least another season to acquire the equipment before a big crop.  We haven’t picked them yet because you’re supposed to wait until the first frost for the sugars to set like you do for apples.  Plus they have just barely started to turn purple.