Off the Grid: Sally breaks down Ab Initio

There are spoilers ahead. You might want to solve today’s puzzle before reading further! Ab Initio
Constructor: Malaika Handa
Editor: Amanda Rafkin
AB INITIO: Each theme answer has the initials A.B.: AIR BUBBLE, ANDRE BRAUGHER, and APPLE BUTTER.
AB INITIO is a Latin phrase that means “from the beginning.” Today, the word INITIO is tipping us off that the theme is found at the beginning of the words, and at the start of the words we find the letters A and B. Although I’ve heard the phrase AB INITIO before, it’s been some time, and I might not have been able to tell you what it means without looking it up. Fortunately, the “INITIO” is similar to “initial,” which was enough of a clue for me to figure out the theme. Thank you, Malaika, for this excellent puzzle.