I well remember the taste of Welch's® concord grape preserves from when I was a child. It was certainly superior then to any grape jelly. These many years later I create that type of high quality product from my own supply of concord grapes from my grape arbor. Actually, that grape arbor is a pergola that the grape vines take over each year, even with careful pruning, and thus I have a large crop of grapes at an inconvenient height that require me to use a ladder to harvest them! It is actually pretty simple.
Having looked at a lot of Internet recipes for grape preserves I did my typical method of combining and modifying the recipes to produce what I figured would be a superior product. In this case, that means retaining the maximum taste from the fruit, which means limiting the amount of sugar to only what is needed, and also making a product that is preserves, not jelly.
My good friend Loren and I made a test batch that turned out well but still required a few improvements. What I learned from yet another Internet search was that the grape skins should not be processed through a colander with the grape pulp, but reserved and added to the processed grape pulp right before the long simmering process that thickens the preserves. I also learned that the lemon juice called for in some recipes was not necessary as the concord grapes have plenty of natural acids (tartaric and malic acids). Thus, to avoid having to add additional sugar to overcome acidity I simply eliminated the lemon juice from the recipe. The goal was/is to have a product that tastes like grapes instead of purple sugar glop.
Note that I use concentrated sodium benzoate solution in this recipe to create a product with a long shelf life that does not require conventional canning procedures once the very hot final product is ready to be put into canning jars. You can buy the sodium benzoate solution from a company named Koldkiss® online, or, you can do conventional canning, which to me is a pain in the butt!
Have fun ... this concord grape preserve is very tasty and attractive. The yield from this recipe is essentially one pint of grape preserves for every two pounds of grapes used. You can scale up the recipe based on your supply of grapes and the size of the pot you will use during the simmering process. You might also decide to bottle the product in half pint jars instead of pint jars.
8 pounds of stemmed concord grapes
1 cup of water
6+ cups of granulated sugar
1 tsp. of butter (to reduce foaming)
2 boxes of Sure-Jell® pectin
1/10 of 1% sodium benzoate (by total weight of product)
Put a small plate in the freezer before starting to test the preserves thickness later.
Remove the grapes from the stems. Wash the grapes in cold water. Discard any grapes that are not perfect.
Remove the grapes from the water in batches of about three cups each, putting them into a large shallow bowl for mashing. Put the grapes into a two gallon stainless steel pot after crushing them with a potato masher and removing the skins and putting them into a large bowl.
Add the water and the butter to the pot and cover the pot with a lid. Heat the mixture over medium high to high heat. Bring to a boil, stirring often with a large wooden spoon. Reduce the heat to low or medium low and boil gently for about 15 minutes.
Process the grapes and water mixture through a colander in batches to press out the pulp into a large bowl and leave the seeds behind. Discard each batch of seeds.
Weigh the processed pulp and the grape skins to help determine the amount of concentrated sodium benzoate solution to add. Adjust the weight upwards by the weight of the 7 cups of granulated sugar. See the Food Nirvana "Dabbling in Science" discussion to determine the exact amount of concentrated sodium benzoate solution to add. Then reduce that amount by 30 percent to allow for later water loss during simmering and thickening of the grape preserves. Weigh the right amount of concentrated sodium benzoate solution out with a reloader scale.
Bring the processed grape pulp and skins to a simmer (low boil) on high heat and stir in the sugar, sodium benzoate and pectin. Reduce the heat to low or medium low and simmer for two hours or more, stirring thoroughly every ten minutes.
After the first hour, test the thickness of the concord grape preserves about every twenty minutes by smearing a small bit across the chilled plate from the freezer. If it gels/sets up it is ready/completed and it will thicken even further later. If not, wash the plate and return it to the freezer and continue simmering and stirring the grape preserves.
Note that as the water evaporates and the temperature rises that the preserves will go from fairly liquid to becoming thicker. Once the mixture starts to become thicker the stirring is increasingly important to avoid burning the product onto the inside bottom of the pot. Do it at five minute intervals.
Test for taste. Add one cup of sugar if necessary, then mix and simmer for 5 more minutes. Repeat the chilled plate and taste steps until the preserves have the desired degree of sweetness and thickness. Mostly this is a matter of personal taste. One of the Internet recipes indicated that the temperature of the concord grape preserves will be around 220 degrees F by the time the right degree of thickness is achieved.
Dispense the hot product into clean half pint or pint canning jars that you first washed with very hot water, and immediately seal them. Check the jars when the product has cooled to room temperature to make sure the caps sealed.
Note: The addition of the sodium benzoate to the concord grape preserves, combined with immediate processing of the very hot preserves into canning jars, is intended to result in a product that can be stored in a food pantry like other canned goods. Refrigeration should not be required until a given jar is opened for use. Use the concord grape preserves within one year.