The wood processing industry generates large amounts of forest residues like branches and tops which represent a significant unexploited resource for sustainable biofuel production. A feasible thermochemical route to valorise these residues is fast pyrolysis. However, the main product of this technology, pyrolysis oil or bio-oil, shows several disadvantages in comparison with conventional fuels. One of the main drawbacks of bio-oil is its instability which results in liquid phase separation in many cases. The purpose of this study is to verify whether homogenous single-phase heating fuels for district heating etc. can be formed from aged, phase separated forest residue pyrolysis oils by blending. Aged, phase separated pyrolysis oils were blended with either methanol or 1-butanol and the amount of alcohol needed to form homogeneous and storage stable fuel blends was evaluated. Homogeneity of the fuel blends was analysed by water concentration profile analysis and image analysis. Storage stability was analysed by analysing homogeneity as function of storage time. Essential fuel characteristics were analysed. The results revealed that phase separated forest residue pyrolysis oil can be homogenized by adding moderate amounts of alcohol and that some of the blends are stable longer than two months. Alcohol addition also improves essential product properties for pyrolysis oils as heating fuels. This work forms part of the ReShip Project partly funded by the Research Council of Norway (The ENERGIX programme).