An apparatus that includes a vessel. The vessel is partially filled with a product to be defrosted. The vessel rotates about an inclined axis. The vessel includes means to move the product during defrosting. The apparatus includes a temperature-measurement-means located at partially inside the vessel to determine a surface temperature of the product and a temperature of liquid surrounding the product without contacting the product and without contacting the liquid. The temperature-measurement-means remain stationary while the vessel rotates.
