This weekend while walking the streets of Chinatown, I ran into Tom Brownstanding outside the Passenger. He was trying to absorb the last few rays of  sunshine before taking his turn behind the bar. We got to talking, and he mentioned the latest madness among bar drinkers: those who ask for a shot of Jameson chased by a shot of pickle juice.

It’s known as the “pickleback,” and it’s become a hit in bars across the country.

I made a face.

Brown personally disdains the combination but, more problematic, the combo drains the juice from the pricey pickles that he and brother, Derek Brown, buy to accompany their sandwiches, like that wonderfully pungent link known as the kimchi hot dog. Tom has already made his feelings public about the Jameson/pickle juice combo.

He thinks the trend started in Philadelphia and trickled its way down to D.C.  (Though the New York Times credits a Brooklyn bar.) Now before you start dissing on our brothers and sisters up North, you might consider this: They may be onto something (though a little off-course).

When I stopped at the Sidebar last week to bid farewell to Tiffany Short, she told me about the latest trend among bartenders: concocting your own “shrub,” which is a vinegar infused with fruit. Short had her own shrub right there at the bar.

On its own, the shrub is a big puckering wallop of sour, unfit for human consumption. I know: I sneaked a straw from the bar and tried it straight. But when mixed into the right cocktail, it can add an extra level of complexity to a drink, an added layer of sour underneath all the other flavors.

Short, for example, mixed me one of her latest creations: a drink made with Rittenhouse rye, egg whites, her homemade shrub, and ice. When shaken thoroughly and topped with a little soda, it made for a frothy, slightly spicy but mellow libation — with this excellent undercurrent of tang. If you’re  a fan of sour margaritas prepared with a quart of fresh lime juice, you’d love this shrub-based cocktail. The puckerish properties are there, but in far better balance.

I’m working on Short to see if she’ll share the recipe. More later.