The FCC (Food Chemicals Codex) method for Nonvolatile Residue in Ethanol measures the amount of residual, non-evaporative material left behind after ethanol is evaporated under controlled conditions. This test helps determine the presence of impurities such as sugars, salts, or other nonvolatile contaminants, which may affect the purity, taste, or suitability of ethanol for food, beverage, or pharmaceutical use.