Since bubbles popping are a random and impulsive source, the spectrum of the detected noise will be the resonance of the glass plus a white noise floor. 48khz

Since bubbles popping are a random and impulsive source, the spectrum of the detected noise will be the resonance of the glass plus a white noise floor. 48khz is not overkill. Acoustic emission sensors used to detect signals like this typically use many times that sampling rate.