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Higher <i>tert</i>-Butyl glycerol ethers (<i>t</i>BGEs) are interesting glycerol derivatives that can be produced from <i>tert</i>-butyl alcohol (TBA) and glycerol using an acid catalyst. Glycerol <i>tert</i>-butylation is a complex reaction that leads to the formation of five <i>t</i>BGEs (two monoethers, two diethers, and one triether). In order to gain insight into the reaction progress, the present work reports on the monitoring of glycerol etherification with TBA and <i>p</i>-toluensulfonic acid (PTSA) as homogeneous catalysts. Two analytical techniques were used: gas chromatography (GC), which constitutes the benchmark method, and ¹H nuclear magnetic resonance (¹H NMR), whose use for this purpose has not been reported to date. A method for the quantitative analysis of <i>t</i>BGEs and glycerol based on ¹H NMR is presented that greatly reduced the analysis time and relative error compared with GC-based methods. The combined use of both techniques allowed for a complete quantitative and qualitative description of the glycerol <i>tert</i>-butylation progress. The set of experimental results collected showed the influence of the catalyst concentration and TBA/glycerol ratio on the etherification reaction and evidenced the intrinsic difficulties of this process to achieve high selectivities and yields to the triether.