What You Need to Know
Dielectric heating causes dipole rotation and ionic conduction in polar solvents such as water or ethanol, generating internal heat that raises the temperature of coffee grounds to 60–120 °C within minutes. This rapid heating increases mass transfer rates of lipids, yielding up to three times more oil than conventional Soxhlet extraction while preserving heat-sensitive aroma compounds if temperature is controlled.
The Science
Primary Reaction
Dielectric heating of polar solvent within coffee grounds leading to rapid temperature rise and enhanced mass transfer of lipids