Ranking lists of periodicals in different scientific disciplines are generally based on the total number of citations derived from a group of source journals with equal weightage given to all citations irrespective of chronology. As a result, in all these ranking lists, the position occupied by the post-war journals, may not be an accurate index of their demand or usefulness to research workers in the concerned field. This may happen because the quantum of published literature in the new journals is limited by the period for which they have been in existence, which is in many cases less than 20 years. Moreover, many of the post-war journals appearing in all these recent ranking lists have started publication even after 1960s, and their enumerated citations cover in fact a variable period of less than 20 years unlike in the case of pre-war journals. To avoid such discriminating against new journals which necessarily have fewer citation credits Sengupta suggested earlier an off-setting weightage formula which has been applied in this paper to rerank microbiology periodicals. A revised ranking list in the field of microbiology has been recommended in preference to the earlier one compiled by Sengupta. Results and findings, after application of the weightage formula, have been presented and discussed in this paper.