Trehalose is a white crystalline powder with purity over 99%, odorless and faintly sweet. Its anhydrous form melts at 203–205 °C and decomposes when heated further. At 25°C, its vapor pressure is extremely low, with a relative density of 1.51 at 20°C. It dissolves easily in water, slightly soluble in ethanol, and does not dissolve in ether or benzene. It stays stable under normal conditions, yet may react with strong acids at high temperatures and be affected by specific enzymes.