Homemade Nectarine Jam Recipe

This fruit-forward nectarine jam is an excellent addition to your pantry! Tasting the flavor of summertime in mid-winter? Winning!

4 from 1 vote

Print Pin

Servings: half-pint jars

Author: Kris Bordessa, National Geographic author

Prepare the calcium water:
Combine ½ teaspoon calcium powder (from the small packet in the box of Pomona’s pectin) with ½ cup water in a small jar. Screw on a lit and shake until well-combined. You'll have more than you need for this recipe. Store the excess in the refrigerator for use in making additional jam or jelly recipes.
Wash the jars you'll use, making sure each is clean and free of nicks in the rim, which could impede sealing.
Wash the lids and rings in hot soapy water. (If you're using non-Ball brand lids, prepare as suggested by manufacturer.)
Place empty jars in a canning pot or large stock pot with enough water to cover by an inch or two, cover pot, and set on high heat. It can take awhile for the water to heat, so get it started before you begin making the recipe.

Wash and dry the nectarines. Cut into quarters or rough chunks. No need to peel them.
6 - 7 pounds nectarines
Mash nectarines coarsely with a potato masher or pulse in a food processor; measure 8 cups into a large pot. Add the prepared calcium water and lemon juice; stir to combine well.
8 teaspoons calcium water, 1/2 cup lemon juice
In a separate bowl, combine the sugar with the pectin powder (the large envelope) until thoroughly combined.
6 teaspoons pectin powder, 2 cups sugar
Bring mashed nectarines to a full boil. Add sugar mixture, stirring vigorously for a couple of minutes to dissolve the pectin. Return to a full boil, boil for one minute, and remove from heat.

Ladle hot jam into half-pint jars to within a quarter inch of the rim. A canning funnel makes this easy.
Wipe jar rims to remove any jam that may have spilled. A clean rim is essential to a good seal.
Set jar lids in place. Screw bands on finger tight.
Use a jar lifter to gently submerge jars into the hot water bath. Be sure to place a wire rack in the bottom of the pot to prevent the jars of peach jam from sitting directly on the bottom. Water should cover the top of the jars by an inch or two. The water will cool somewhat in reaction to the addition of the jars. Return the water to a low boil and then set the timer.
Process in a boiling water bath for 10 minutes. Add a minute to the boiling time for every 1,000' above sea level.
Check seals. Lids should be solid and pulled down tight. (if they flex and pop, the jar didn’t seal; put unsealed jars in the refrigerator and use those first).
Remove rings and wash outsides of jars. Store in a cool, dry place.

Recipe yields 10 half-pint jars.
This recipe is made using Pomona’s Universal Pectin. This is the only pectin I use anymore as it allows me to use much less sweetener. The standard pectin brands use an obscene amount of sugar in my opinion, often requiring equal amounts of sugar and fruit! This product uses a low methoxyl method and calls for using two different ingredients, which are included in the box: pectin (the large packet) and calcium powder (the small packet). The dry pectin is mixed with the sweetener before being added to the fruit. The calcium is combined with water and added directly to the fruit.
Boiling lids or heating above 180°F as once recommended can damage the sealing compound.
Do not use white nectarines for this recipe; these are less acidic than the yellow variety and can alter the pH of the recipe making it unsafe for canning according to the National Center for Home Food Preservation.
SOURCE: Adapted from guidelines provided by Pomona's Universal Pectin.