I have a question about the recipe "Sheri Castle's Instant Pot Bourbon & Cola Beef Short Ribs" from Food52. Any substitution for the coke?
The author's headnote clearly states the cola is added for flavor.
Note that the cola adds some acidity as well (many soft drinks are highly acidic). I'm sure you could replace it with water, you'll just have less sugar and acidity, so it'll probably be more bland.
If you replace it with another sweet soft drink (like Sprite), you'll likely have a different flavor profile than what the recipe author intended.
Your call on whether or not you want to change the flavor profile. After all, you are putting it on your dinner table for you and your dinner guests.
Best of luck.
I know someone who uses Dr. Pepper. Personally, I like to use a hard cider.
Won't give identical taste, but some brewed black coffee might be a nice su for the cola. Goes well with the bourbon, and there ard many beef recipes which use it (wet or as a rub).