Two variants of an inflection point (IP) method for analysis of large sets of spectra, acquired in real time during non-plasmonic to plasmonic glass transformation are proposed. One of the variants is based on the time evolution of the spectral inflection point position, IPP, while the second one follows the time evolution of the spectral inflection point slope, IPS. Both methods yield activation energy (AE) of the metal precipitation in strong agreement with previously reported values, obtained via the standard kinetic approaches. The proposed IP methods are blind to the surface plasmon resonance (SPR) band shape. Most importantly, the IP analysis allow for robust uncertainty assessment at every step via standard bi-Gaussian fitting. Theoretical association between the proposed IP parameters and the traditional kinetic, and spectral models is elucidated. The IP methodology is applicable to various noble metal nanoparticles in a wide range of sizes and embedded in various dielectric matrices.