Step 1

In a non reactive pan, whisk together sugar and salt. Stir in the water and lemon juice.

Step 2

Turn the heat to medium high and stir in the blueberries, bring to a boil.

Step 3

Once boiling, cook for 2 minutes stirring constantly, scraping the bottom to prevent burning.

Step 4

Use an immersion blender or a food processor to puree the syrup for a smoother, thicker syrup.

Step 5

Stir in the vanilla extract, if using.

Step 6

Heat jars in simmering water until ready to use, do not boil.

Step 7

Wash lids in warm soapy water and set aside with bands.

Step 8

Ladle hot syrup into a hot jar leaving a 1/4 inch headspace.

Step 9

Remove air bubbles. Wipe jar rim. Center lid on jar and apply band, adjust to fingertip tight.

Step 10

Place jar in simmering water canner. Repeat until all jars are filled.

Step 11

Bring water to a boil and process jars 15 minutes, adjusting for altitude.

Step 12

Remove jars and cool 12-24 hours.

Step 13

Check lids for seal, they should not flex when center is pressed.

Step 14

Label and sore in a cool dry place and use within 18 months.

Step 15

Once syrup is opened, store in the refrigerator.