Try this research-tested recipe for blackberry jam courtesy of the National Center for Home Food Preservation.
- 6 cups, Blackberries, crushed (about 3 quart boxes)
- 1 package, Powdered pectin
- 8 ½ cups, Sugar
Yield: Makes about 11 or 12 half-pint jars.
Sort and wash fully ripe berries. Remove any stems or caps. Crush berries. To reduce seediness, place berries through a sieve or food mill.
- Measure crushed berries into a kettle. Add pectin and stir well.
- Place on high heat and bring quickly to a full boil with bubble over the entire surface; stir constantly.
- Add sugar, continue stirring, and heat again to a full bubbling boil. Boil hard for 1 minute, stirring constantly. Remove from heat and skim the surface.
- Fill hot jam immediately into hot, sterile jars, leaving ¼-inch headspace.
- Wipe rims of jars with a dampened, clean paper towel. Secure lids and process in a water bath canner for 5 minutes (Altitudes above 1,000 ft require an increase in processing time).
To learn more about canning Jams & Jellies, watch our Troubleshooting Jams & Jellies video!
- Rim of jar must be free of all food particles in order to ensure seal adheres appropriately.
- Instructions on water bath canning can be found in this resource.
SDSU Extension recommends using evidence-based recipes when engaging in food preservation at home. The recipe above has been research-tested and provided by the National Center for Home Food Preservation. Do not modify ingredients.