Submerge your glass bottle or jar in a pot of boiling water to cover by 1 to 2 inches, and boil for 10 minutes. For the lid or cap, wash it in hot, soapy water; rinse well; and scald in boiling water.

Carefully remove the bottle or jar from the water using tongs and place on the counter.

Combine the sugar and kosher salt in a small bowl.  Pick off the leaves of the mint sprigs and clap them between your hands once to release the oils.

Wash and cut the rhubarb and start layering the rhubarb, sugar and mint into the bottle or jar.  Seal with the lid on and leave it on the kitchen counter for a few hours until some liquid start to get drawn out from the fruit. Place in the refrigerator.

Twenty-four hours after you first combined the sugar mixture with the fruit, add 1 cup red wine vinegar (or use cider or white wine vinegar). After adding the vinegar, leave it at room temp for a few hours, then taste it to see if it needs more vinegar (up to ¼ cup more). Shake up the jar a few times, and put it back in the fridge for a minimum of 24 hours. (You can leave it for several more days if you’d like to develop an even deeper flavor).

Strain the fruit from the vinegar solution through a damp cheesecloth or coffee filter. Save the fruit for another purpose- it makes for a great topping on yogurt or make a chutney or jam from it!

To serve, mix 1 tablespoon shrub syrup into a glass of still or sparkling water. Taste and add more syrup, if desired.