Preparing Grape Juice for Jelly

What is the difference between jelly and jam? Jelly is made from the clear juice of the fruit, while jam is made from crushed fruit.  Let's look at how to prepare juice from grapes for this classic product.

Preparing the Juice

1. Use Fresh Grapes. For best results, begin the preservation process within 24 hours of picking. If you are unable to process the grapes immediately after harvesting, refrigerate the unwashed grapes.
2. Preparation of Grapes. Wash hands for 20 seconds. Pull the fruit off the stems, wash in a container of cold water, and discard any soft or moldy grapes. Do not remove skins from grapes as the pectin is more concentrated in this portion of the fruit. Select about ¼ of the grapes needed at the firm ripe stage and ¾ fully ripe. This is especially helpful when making a long-cooking jelly without added pectin.
3. Extract the Juice. Begin by placing the selected grapes in a non-corrosive pot and smashing with a potato masher until the juice begins to flow. Add only enough water to prevent scorching and bring to a boil. Reduce heat and simmer about 10 minutes. Stir the grapes occasionally while cooking to prevent sticking. Mash the grapes again halfway through the cooking process to break up as many remaining grapes as possible. Extract the juice from the grapes by placing a large sieve lined with two layers of cheesecloth on top of another pot. Another option is to use a jelly bag. Ladle the cooked grape mixture into the sieve and let sit for several hours or overnight in the refrigerator. You can repeat the straining process a second time if you wash the sieve or jelly bag.  A third straining is not necessary. Using a coffee filter will give a clearer juice product.
4. Clarify the Juice. When you take the pot with the strained juice from the refrigerator, do not mix it. Avoid disturbing the sediment on the bottom of the pot. Pour off the clear liquid into a clean container to be used for making the jelly. Sediment on the bottom of the pot should be discarded. Straining the juice is the way to ensure jelly does not contain tartrate crystals.

Grape Jam and Jelly Recipes

• Grape jam and jelly can be made with or without added pectin. 
• Long-cooking grape jam without added pectin requires carefully balancing sugar and juice.  The pectin and acid needed to form a gel come from the juice's natural ingredients.
• Jelly made with added pectin may use regular pectin with high amounts of sugar. There are recipes using liquid or powdered pectin.
• Low- or no-sugar-added pectin grape jelly uses special pectin-containing calcium to form the gel. These usually have a softer set.

Freezer Jelly

Freezer jam is popular because of the ease with which it can be made and because it does not heat up the kitchen. You may be surprised to learn that jelly can be made as a freezer product, too. Freezer grape jelly requires the use of special recipes or special pectin. Freezer jam made with regular pectin uses about double the amount of sugar as the cooked version of the same product.  Special freezer pectin may use only a cup or two of sugar per recipe. Refer to the recipe insert in the pectin box. Freezer jellies are sometimes referred to as instant jelly or as uncooked jelly. Again, if the freezer jelly is made with less sugar, the consistency of the jelly is usually softer.

References

National Center for Home Food Preservation. (n.d.). Grape Jam without Pectin. University of Georgia.  

National Center for Home Food Preservation. (n.d.). Grape Jelly Liquid Pectin. University of Georgia.  

National Center for Home Food Preservation. (n.d.). Grape Jelly Powdered Pectin. University of Georgia.