The solvent fractionation method based on water extraction has been proven to be an effective tool for characterization of pyrolysis liquids and for studying their storage stability. However, for quality follow-up in pilot/demonstration plants, a simpler and faster fractionation scheme is needed. There is also a need for a rapid method for analyzing the carbohydrate content of pyrolysis liquid. Carbohydrates of pyrolysis liquid cause problems in fuel oil use due to their reactivity and sticking tendency. The new method includes much faster separation of water extract using centrifuge and characterization of carbohydrates by the Brix method. The determination of water content, water-insolubles, and carbohydrates by Brix accounts for 80-85 wt % of pyrolysis liquid composition. The main changes in aging happen between these groups; hence, these changes give information on the quality of pyrolysis liquids.