How should the temperature of sour cream be accurately measured?

Placing a thermometer stem directly in the sour cream after removing the lid is the most accurate method for measuring its temperature. This approach ensures that the thermometer is submerged in the product, allowing for a precise reading of the internal temperature. Accurate temperature measurement is crucial for food safety because it helps in identifying whether the sour cream is within the safe temperature zone for storage.

Other methods, such as placing the thermometer in the lid or checking the external temperature of the container, do not provide a reliable indication of the product's actual temperature. Shaking the container would not yield an accurate measure either, as it does not address the temperature of the cream itself but rather only the surface or external aspects of the packaging. Thus, direct contact with the substance in question leads to the best understanding of its safety and quality regarding temperature control.