And guess what, I'm converted.
From what I can gather, a shrub is just an old fashioned method of preserving fresh fruit. You use vinegar and sugar and boil the fruit, then it lasts indefinitely in the fridge. The tangy syrup makes a surprisingly refreshing (and not mouth puckering) cocktail.
Another advantage is that it's so dang easy. You can whip up this shrub in less than 10 minutes and all you have to do for the actual cocktail is stir and combine. No shaking, no finicky measuring or complicated ingredients. Just a 1:3 ratio of shrub to bourbon, topped with a bit of sparkling water.
Bourbon cranberry shrub (original recipe isn't posted yet - I've tweaked the instructions to make them more clear and converted the measurements to ounces)
Cranberry shrub -
1 cup white wine vinegar*
1 cup sugar
1 cup cranberries
Combine in a pot and bring to a boil, stirring to dissolve all the sugar. MS doesn't specify, but I cook until the cranberries are split but not turning to mush. The cranberries will usually start popping shortly after the liquid comes to a boil and that's when I turn off the heat. I like them to hold their shape a bit.
Remove from heat and let cool completely. Refrigerate for up to three weeks.
For each cocktail -
3 oz bourbon
1 oz shrub
1 oz seltzer
+ some of the soaked cranberries
5 oz is a pretty big cocktail in my opinion, so if I'm making them individually I'd split a single cocktail between two glasses. This does make the serving tiny bit small, but better than knocking everyone out before dinner.
But there's no need to worry about that! This makes a perfect pitcher cocktail as well. I just combined the bourbon and shrub ahead of time at a 3:1 ratio. Three cups of bourbon + 1 cup of shrub worked well for pre-dinner cocktails for 10 adults. I set out a flip top bottle of sparkling water on the cocktail tray and poured the first round for everyone, just doing about 3/4 of the bourbon/shrub mixture and 1/4 water. Then it's easy enough for people to pour their own to their liking. If you want to make it a bit fancy, you can spear the shrub cranberries ahead of time and just use them as the stir stick in each cocktail. Of course, you can also just set out a bowl of the cranberries and a small spoon and scoop them into each drink.
* You do need to use white wine vinegar. In a fit of impatience, I tested this out first with white balsamic vinegar and it was way sweeter and more syrupy. I'm guessing that straight white vinegar would be too acidic.