Yield: 8 pints or 16 cups
- Sterilized canning cars; 16, 1 cup size or 8, 1/2 pint size. I run the jars through a dishwasher cycle to sterilize.
- Canning funnel, jar holder, and lid holder (also sterilized)
- 6-quart pan or copper jam pan
- Large stock pot with lid
- 8 lbs. ripe strawberries, cleansed and dried. (Buy smaller, firmer varieties such as Chandler and Seascape. These should be the best quality you can afford and only while in season. Use strawberries immediately. See sources below.)
- 4 lbs. sugar
- 4 Tbs. lemon juice
- 1 Tbs. and about 1/8 cup balsamic vinegar (used separately)
- Cut berries in half and then in three thin slices for each half.
- Combine fruit with the sugar and lemon juice in a pan.
- Let sit until strawberries let out a bit of juice -- about 1/2 hour.
- Mash berries with a potato masher and then bring to boil over high heat.
- Reduce heat to low boil and cook until the gel point. (See finishing temperature and altitude chart at bottom of page.)
- While the jam is cooking to the gel point, fill a large stock pot about 3/4 high with water and place over high heat. You will use this to can your finished jam.
- When jam has reached gel point, skim off foam.
- Add balsamic vinegar, and stir.
- Place the jam funnel on the lip of the jars, and ladle the jam mixture into the sterilized jars.
- Leave about 1/4-inch of space between the top of the jam and the jar top.
- Wipe the rims thoroughly with a clean, damp paper towel.
- Close the jars, but not too tightly.
- Use the jar holder to lower jars into the boiling water in the stock pot. Make sure the jars are covered by at least 2 to 3 inches of boiling water.
- Cover stock pot and continue cooking on a low boil for 10 to 12 minutes.
- Remove jars with jar lifter and let cool on a wire rack. You should hear a pinging sound as the jars seal. When cool, remove outer rings and check each jar for a good seal. The inner ring should not separate from the jar.
- Dry the outer rings to prevent rust. The next day, after the jam is cool, screw the outer rings back on the jars.