An alternative method is proposed as a means for providing a closure for the sub-grid-scale variance, which is a key quantity in reacting flow simulations. The method is based on deconvolution, namely a constrained iterative deconvolution method combined with explicit filtering. The assessment of the method is conducted a priori using a direct numerical simulation database, and for the conditions tested in this study the method is found to provide quantitatively good estimates of both the un-filtered progress variable and its variance.