Sticky-sweet, tangy and rich with black pepper and soy sauce, lemon-­lime lacquered grilled chicken is a staple Filipino street food we knew would be perfect for American-style grilling. And yet it took us a bit of trial and error before we realized exactly why it was so delicious.

Inihaw na manok, which simply means grilled chicken, usually is soaked in a savory-sweet-acidic brine that caramelizes as it grills. But we were surprised to find that the backbone of its sweetness and citrus flavors turns out to be lemon-lime soda.

It may sound like an odd ingredient, but it’s one of many American foods Filipinos adopted following the Spanish-­American War, when the U.S. won control of the archipelago. Nonetheless, at Milk Street, we wondered whether we could skip the soda—admittedly not part of our typical cooking repertoire—and substitute a blend of lemon and lime juice, plus a bit of extra sugar.

To our surprise, the answer was a resounding no. Batches made with the juice and sugar substitute simply weren’t as good as the soda-based original, and it turns out the science backed that up. That’s because high-­fructose corn syrup (the sweetener in most sodas) caramelizes better than sucrose (conventional sugar) when heated, creating more flavor more quickly via browning.

For our version, we opted for chicken parts, rather than the more traditional chunks of thigh meat. We scored the flesh and skin to create more surface area for the sauce to adhere to. We prepared the marinade in the blender, then stirred in soda—Sprite or 7UP—so the carbonation didn’t cause the mixture to explode.

After an hour or two marinating, we grilled the chicken over indirect heat, brushing on extra marinade we’d reduced to a thick glaze. A quick turn over high heat transformed the glaze into the sticky-sweet coating we wanted. The result? A balanced sweetness kept in check by sharp pepper, savory bay and soy sauce, and the tang of vinegar.