Even if you’re used to the signature Momofuku move of white-knuckle bungee jumping from the high end to the low, certain juxtapositions may call for Dramamine. Alongside the masterly pork pie, you can find a $5 sandwich of pickled daikon and cucumber sticks inside a grilled and buttered Martin’s hot dog roll. The pickle sandwich is just the thing to eat with the cold fried chicken that is battered three times, fried four times, brushed with a spicy mirin-yuzu glaze and served nearly at refrigerator temperature. I don’t believe I’ve used that phrase approvingly in a review before, but then I don’t think a restaurant has served me cold fried chicken as good as this before.

By flipping through the menu pages you can pinpoint the dates when dishes were first served, and see others that came and went. The idea is for Ko’s executive chef, Sean Gray, to use the bar as a “field for research and development for our culinary team,” according to the website. Ideas are auditioned or refined before they graduate to Ko, which I gave three stars in a 2015 review. Most menus, at least the ones that change over time, are works in progress, but few make that explicit the way the one at Ko’s bar does.

The cynical way to look at this is that bar customers are paying to serve as lab rats. This will not be everyone’s idea of a fun night out. One recent evening, the menu was as meat-heavy as at Ssam Bar in the era when its menus still proclaimed, “We do not serve vegetarian-friendly items.” Among the more substantial dishes that night was a mixed-meat sausage stuffed into a chicken neck and grilled. One end of the neck was open. The other was still attached to the chicken’s head. It was a sensational sausage, but it did nothing to make Ko’s bar the kind of place that you’d take your new pescatarian friend.

The bar, run collaboratively by Mr. Gray and Su Wong Ruiz, the general manager, works best for diners who don’t need a multitude of choices to be happy. To the extent that it resembles other places, it’s probably most similar to a wine bar, with its tight menu, its casual drop-in-and-stay-awhile air and its carefully considered list of wines by the glass, which it shares with Ko. Anyone who wants a whole bottle can order one from the full Ko list, a virtual who’s who of cult winemakers in certain specialties such as grower Champagne, chenin blanc from the Loire Valley and Burgundy of all stripes.