Wash the blueberries and measure them by weight of package or putting them into a measuring cup.

Place them in a large jar or a bowl you can cover later.

Add sugar: I generally add about ¾ cup to 1 cup of sugar for each 2 cups of berries.

Add lemon juice, the zest, and the fresh sage.

Muddle the fruit and sugar mixture with a muddler or potato masher.

Stir well, cover tightly, and set aside for 2-3 days. You can stir the bowl or shake the jar a couple of times a day if you like.

After 2-3 days, the mixture should be juicy. Strain it into a bowl, gently pressing the fruit to extract as much juice as possible without pressing the fruit through the sieve.

Measure it and add an equal amount of apple cider vinegar (or other vinegar).

Strain through a cocktail sieve into a jar or bottle; cover tightly and refrigerate until ready to use. You can try it now, but the flavors will meld, marry, and get happy over the next weeks.