US Patent 7244461 Method of preparing liquid smoke

The invention relates to a method of preparing a smoke extract, which method comprises the steps of i) preparing a char from wood or cellulose preferably by pyrolysis, ii) extracting one or more fractions of the char with an extraction solvent in its supercritical state and/or an extraction solvent in its liquid state, said solvent in its supercritical state being selected from the group consisting of CO2, propane, methane, ethylene, ammonia, methanol, water and mixtures of one or more of these solvents, said solvent in its liquid state being selected from the group consisting of CO2, propane and mixtures of these components, iii) collecting at least some of the extracted char to thereby obtain a smoke extract.