Quantification and characterization of urban food waste (UFW) and bulking agents is essential to obtain the best compost recipe for an accelerated process, minimal odor emissions and limited leachate production. For downtown Montreal and from May to August 2004, the study examined monthly variation in carbon (C), nitrogen (TKN), C/N ratios and dry matter (DM) of food waste (FW). The FW was collected from residences, a restaurant and a community kitchen. Locally available bulking agents were also analyzed to compare characteristics for the best composting process. Furthermore, trials were conducted using an urban composting unit prototype to compare the performance of various recipes. In each trial, temperature and pH were recorded every day and other day, respectively. The C, TKN, C/N ratio and DM of the UFW were found to vary from 49.3% to 47.9%, 1.7% to 2.7%, 29.1 to 17.9 and 13.7% to 10.3% from May to August respectively. These variations resulted from more fresh vegetables and fruits being consumed by the end of the summer. The C/N ratios of chopped wheat straw (CWS) and chopped hay (CH) were found 100 and 58 with DM of 89% and 91%, respectively. From trial experiments, the best ratios (weight basis) of UFW to CWS and CH were found to be 8.9:1 and 8.6:1, respectively. Thus, the composting recipe m ust be adjusted regularly to correct for variations in UFW characteristics.