(Adapted from various online sources)
I make absolutely no claims to historical accuracy with this recipe. I got tired of driving 3 hours and shelling out mucho dinero for a 12-oz bottle of ginger shrub, and figured I'd make my own. The first batch, plain ginger, came out ok. I decided to get a bit adventurous, and added some kick to it. Here's the result.
(small batch, scale up to fit)
2-to-4 oz fresh ginger root, peeled and chopped
1 tsp (or to taste) cloves
1 tsp (or to taste) cardamom seeds
1-1/4 cup water
1 cup sugar, or sucralose (aka Splenda) if you want no-carb.
½ cup vinegar (I use cider)
In a blender jar, grind the cloves and cardamom to powder. Shred the ginger in a blender or food processor. Put in a pot with lid, with the water. Use the water first to rinse the blender jar(s) and capture all the good stuff.
Bring the pot to a boil, cover, turn to warm / low, and simmer for one hour. Strain the infusion into a mixing bowl, being sure to stir and press the mixture to get all the liquid you can. Measure 1 cup of the liquid, and combine it with the sweetener-of-choice, and the vinegar.
Decant into a suitable glass container, and let it sit for a couple or three days to settle. Remaining particulates will settle to the bottom. You can then pour off the clear liquid into your nice container-of-choice. Between the sugar and acid contents, this has a pretty good shelf life. You can refrigerate or keep it in a cooler, if you wish.
Generally, I use 1-2 tablespoons or so with a cup or so of cold water. If you're the drinking sort, I'm told that it goes really well in a mix of 1 oz shrub, 1 shot dark rum, and top with water.