Mustang Grape Jelly is definitely a Texas Jelly. While there are a total of 14 wild types of grape in Texas, the jelly I have made is from Mustang Grapes, which is the most common grape in the eastern half of the state, including the Hill Country. It ranges from southwestern Texas up to Oklahoma and even into Louisiana and Arkansas. The fruit are sour, dark purple grapes, and the largest in Texas. 
I did spot another type of grape beginning to develop but I was not familiar with it nor was it ripe yet. The Mustang Grapes are ripening now and will continue to be ripe for several weeks yet. Now is a good time to check out your favorite site. As mentioned in an earlier post, grape vines are quickly spotted even while zipping down the freeway in your car so you can easily find all the vines you need. Some plant will be male so you will need to find the ones with the fruit. Bring a scissors or clippers with you to cut the clusters of grapes off the vine. Wear gloves so you don’t irritate your skin while picking the fruit. Grape jelly can be made with any variety of grape so even if you find another variety of grape the jelly will turn out great. Because the fruit is so sour it makes a very refreshing jelly, since it retains enough of the tartness to remind you it came
After separating the fruit, and washing them you are ready to begin. You will need approximately 10 cups of fruit. Crush the fruit with a potato masher, a food processor, blender, or juicer. Heat the fruit on the stove until you have juice. Pour the mix into a food mill to extract more juice. Then pour through a cheese cloth or jelly bag. Then add the sugar. After a minute’s hard boil add the pectin. Cool and then pour into freezer containers. After assuring that the jelly has set, freeze the jelly. I use large containers so that they are easier to stack in the freezer.
Grape Jelly Recipe 
4 cups Grape Juice
3 cups sugar
1 pkg No sugar-needed fruit pectin
My Grape Jam was made due to the amount of cooked pulp left over from making jelly. The pulp had already gone through the food mill and then had been left behind in the cheese cloth. I then added sugar and pectin. Obviously one could make this without making jelly first.
Grape Jam Recipe
4 cups Grape Pulp
3 cup sugar
1/8 tsp cinnammon
1 pkg No sugar-needed fruit pectin
Try Agarita and Mesquite Jellies…maybe a new Retama Jelly???
Agarita is one of my favorite jellies. Mesquite made a light yellow color jelly. As far as Retama I am not familiar with making a jelly out of it. I have read that a tea can be made from the ground beans.
Do you know why some mustang vines product grapes while others bud, flower and then no fruit. They look the same and are yards away from each other
Yes, Ray, unlike cultivated grapes, wild grapes have male flowers on one vine and female flowers on another. Thus the male grape vines will produce flowers but no fruit. If you have more than one male vine in the area you could eliminate the surplus males.