Joe,
Extract the seeds and dry them out. Then store them in the refrigerator. Do not freeze them.
You will probably not get the same vine if you plant seeds. The pollen that produced the fruit could have come from anywhere and any kind of grape. If you want the same kind of vine, take cuttings.
Wait until the late winter (February) and take a few cuttings off the vine. They should have 3-4 nodes (joints). Make sure you can tell which way is "up" on them so they are not planted upside down. Wrap the cuttings in moist (not dripping wet) paper towels or newspaper, place inside a plastic bag, and store in the refrigerator. They will keep for several months.
To do this right, they should be caloused, but if you don't know what that is then forget it and just plant them in the ground in the Spring. Plant them with only one node above ground. Keep the soil moist but not soggy. Plant 4-5 (without calousing) to ensure you get one that survives. Plant seeds only as a backup.
Jack Keller, The Winemaking Home Page
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