The most difficult thing about harvesting muscadines is knowing when to harvest them. Muscadines will typically grow in bunches, but they don’t all ripen at the same time, so they must be picked individually. If you pick them too early, they will not ripen any further and at best, you’ll have fruit that is not as sweet as is should have been. Take a look at the photo below and tell me how many of those are ripe and ready to be picked.
The answer is none of them. The first thing you are looking for is color. These muscadines are Ison’s, so you are looking for ones that are black. The second thing you are looking for are fruits that have dulled slightly. The shiny fruits are not quite ready. In the photo, you can see a slightly dull fruit about two-thirds of the way down on the left side. There is a smaller fruit in the upper right nested beside 4 green fruits. On those two, I would grab them and feel how firm they are. In both cases, they were tight and still held on to the vine. When they are slightly less tight and more easily release from the vine they will be ready. The best way to tell is to follow these guidelines and once you’ve picked one, taste it. When in doubt. leave it for next time.