Michigan State University Extension
Preserving Food Safely - 01600890
Wash and rinse all fruits thoroughly before cooking. Do not soak. For best flavor, use fully ripe fruit. Remove stems, skins and pits from fruit; cut into pieces and crush. For berries, remove stems and blossoms and crush. Seedy berries may be put through a sieve or food mill. Measure crushed fruit into large saucepan using the ingredient quantities specified in the table below.
Cups Crushed Cups Tbsp. Yield Fruit Fruit Sugar Lemon (Half-Pints) Juice
Apricots 4 to 4-l/2 4 2 5 to 6
Berries* 4 4 0 3 to 4
Peaches 5-l/2 to 6 4 to 5 2 6 to 7
*Includes blackberries, boysenberries, dewberries, gooseberries, loganberries, raspberries, and strawberries.
Add sugar and lemon juice and bring to a boil while stirring rapidly and constantly. Continue to boil until mixture thickens. Use one of the following tests to determine when jams and jellies are ready to fill. Remember to allow for thickening during cooling.
Temperature test--a jelly or candy thermometer and boil until mixture reaches the temperature for your altitude.
Sea l000 2000 3000 4000 5000 6000 7000 8000 Lev. Ft. Ft. Ft. Ft. Ft. Ft. Ft. Ft.
220 F 218 F 216 F 214 F 212 F 211 F 209 F 207 F 205 F
Refrigerator test--Remove the jam mixture from the heat. Pour a small amount of boiling jam on a cold plate and put it in the freezing compartment of a refrigerator for a few minutes. If the mixture gels, it is ready to fill.
Remove from heat and skim off foam quickly. Fill hot sterile jars (see directions below for sterilizing jars) with jam. Use a measuring cup or ladle the jam through a wide- mouthed funnel, leaving l/4-inch headspace. Adjust lids and process.
Sterilization of Empty Jars
To sterilize empty jars, place them right side up on the rack in a boiling water canner. Fill the canner and jars with hot (not boiling) water to 1 inch above the tops of the jars. Boil 10 minutes at altitudes of less than 1,000 feet. At higher elevations, boil 1 additional minute for each additional 1,000 feet elevation. Remove and drain hot sterilized jars one at a time as filled.
RECOMMENDED PROCESS TIMES FOR JAMS WITHOUT ADDED PECTIN IN A BOILING-WATER CANNER
Process Times at Altitudes of
Style of Jar 0- 1001- 6001- Pack Size 1000 ft. 6000 ft. 8000 ft.
Hot Half-pints 5 min. 10 min. 15 min. or pints