1. Choose the best fresh grapefruits that are mature, firm, ripe, and have a slight give when pressed. You’ll need 13 pounds of canning fruit for a 9-pint load or 15 pounds for a 7-quart canner load.
2. Wash 9 pint jars or 7 quart jars with their ring bands and new canning lids using warm water and soap. Rinse everything in warm water.
3. Check that your water bath canner is in good condition, and load it with a clean canning rack. Fill the canner halfway with clean water. Put the canning jars in the canner and apply medium-high heat to bring the water to a constant simmer at 180°F.
4. Use lukewarm water to wash the grapefruit and rinse them using cool running water.
5. Peel the grapefruits using a sharp knife or citrus peeler. Separate the fruits into segments. Remove as much white as possible, including the membranes and pith, as these parts are bitter and spongy.
6. For easy packing and to avoid floating, try to keep the same-size segments together to go into the jars.
7. If preferred, remove the seeds from the segments. Save the grapefruit juice that oozes out during de-seeding and use it in the syrup. Discard the seeds.
8. Make a simple syrup in a large stainless steel pot. Add water and sugar to the pot and heat them while stirring occasionally until all the sugar dissolves. Use the following guidelines for making medium, light, or very light syrup:

Syrup Ratios: 9-pint Load

• Very light syrup: 6½ cups water and ¾ cups sugar
• Light syrup: 5¾ cups water and 1½ cups sugar
• Medium syrup: 5¼ cups water and 2¼ cups sugar

Syrup Ratios: 7-quart Load

• Very light syrup: 10½ cups water and 1¼ cups sugar
• Light syrup: 9 cups water and 2¼ cups sugar
• Medium syrup: 8¼ cups water and 3¾ cups sugar

Filling and Packing the Jars

1. Take out the hot jars, dry them, and fill them with grapefruit segments. Try filling each jar with segments of the same size. Packing the segments tightly will prevent floating after heating, which may tamper with the seals.
2. Ladle the hot syrup over the citrus fruits, allowing ½-inch headspace.
3. Use a wooden skewer to remove air bubbles from each jar.
4. Wipe the rim of each jar with clean paper towels dipped in vinegar to reduce the incidence of false seals.
5. Place new canning lids on the jars and cover them with ring bands to a finger-tip tight position.
6. Using canning tongs to lower each jar into the canner as soon as you cover it with the lid and band. Avoid turning or tilting the jars. Ensure the canner is still at a simmer and the jar tops are submerged 1-2 inches in hot water.
7. Apply high heat under the canner and bring it to a constant boil. Close the canner’s lid and start your timer to process both pint and quart jars with the following altitude and time adjustments:

Processing Times for Raw-pack Grapefruits in a Water Bath Canner

• 0 – 1,000ft: 10 minutes
• 1,001 – 6,000ft: 15 minutes
• Above 6,001ft: 20 minutes

Post Processing

1. After the timer stops and you haven’t lost the boil, get the canner off the heat and remove the lid. Allow 5 minutes for steaming. Remove the jars one by one using a jar lifter or canning tongs. Place them on a raised, flat surface covered with warm cloth towels.
2. Let the jars cool undisturbed and away from draft or air conditioning for 12-24 hours. Do not retighten the lids.
3. Remove each ring band to check the condition of the lids. Press the lids down and check for flexing. Refrigerate any jars that have lids that flex, and eat the grapefruit within 3-5 days.
4. Wash the perfectly sealed jars under cool running water without tampering with the lid. Dry the jars and label them with the contents and canning date. Keep the canned grapefruit jars in a cool, dark, dry place.