Prepare a water bath canner and four half-pint jars, lids, and rings for canning. Place a small ceramic plate or bowl in the freezer.

Combine the cherry juice and St-Germain, then add to a large, heavy jam pan or pot. Heat to boiling, then add sugar and lemon juice. Once sugar is dissolved, add the gooseberry pectin.

Continue to boil the mixture, stirring occasionally and skimming foam as it collects on the surface. Check temperature and begin plate testing when the mixture reaches 220 degrees F. Be sure to stir well and watch for signs of scorching; the temperature may hit 225 degrees F or slightly higher before the mixture passes the plate test.

Once the mixture passes the plate test, remove the pot from the heat.

Ladle the mixture into prepared jars, wipe rims, add lids and bands, and process for 10 minutes after the canning pot returns to a boil.

Remove jars from the canner to a folded tea towel on the counter and leave undisturbed for 24 hours so that jars can seal and the mixture can set properly.