Updated project metadata. During the analysis steps of hydrogen deuterium exchange (HDX) mass spectrometry (MS) there is an unavoidable loss of deuterons, or back-exchange. Understanding back-exchange is necessary to correct for loss during analysis, to calculate the absolute amount of exchange, and to ensure that deuterium recovery is as high as possible during LC-MS. Back-exchange can be measured and corrected for using a maximally deuterated species (here called maxD) in which the protein is deuterated at all backbone amide positions and analyzed with the same buffer components, %D2O, quenching conditions, and LC-MS parameters used during the analysis of other labeled samples. Here we describe a robust and broadly applicable protocol, using denaturation followed by deuteration, to prepare a maxD control sample in ~40 minutes. The protocol was evaluated with a number of proteins that varied in both size and folded structure. The relative fractional uptake and level of back-exchange with this protocol were both equivalent to those obtained with a previous protocol that requires much more time or one requiring isolation of peptic peptides prior to deuteration. Placing strong denaturation first in the protocol allowed maximum deuteration in a short time (~10 mins) with equal or more deuteration found in other methods. The absence of high temperatures and low pH during the deuteration step limited protein aggregation. This high-performance, fast, and easy to perform protocol should enhance routine preparation of maxD controls for both beginners and for challenging proteins.