We develop a method to exfoliate atomically clean and strain-free hBN nanolayers from hBN particles. It has been well recognized that hBN nanostructures are characterized by their excellent thermal and chemical stability and unique electronic and optical properties, providing an ideal building block for the investigation of vdW potentials. Our exfoliation procedure is based on an intercalation-based method; however, unlike conventional methods, it does not require any sonication, sharing nor electrochemical process as a driving force, hence yielding mechanically intact and strain-free samples. Briefly, we start by creating hBN/H2SO4 intercalation compounds by heating hBN powders in an aqueous H2SO4 solution. The resulting solution is neutralized by a solution of NaHCO3 to form sodium sulphate salt in between the hBN layers. We found that this acid/base reaction leads to spontaneous exfoliation of high-quality hBN layers suitable for the characterization of moiré potentials by HRTEM (see the Supporting Information and Fig. for details).