Whether Nutella is considered a liquid depends on the context.
The Transportation Security Administration (TSA) provides guidelines on what is considered a liquid for air travel. According to information provided around World Nutella Day, "if you can pour it, smear it, or spread it, it counts as a liquid." Therefore, according to TSA standards, Nutella is generally treated as a liquid. This means that larger containers of Nutella (over 3.4 ounces) should be placed in checked baggage rather than carry-on bags. Smaller, travel-sized containers (3.4 ounces or less) are permitted in carry-on bags.
Therefore, in the context of air travel and TSA regulations, Nutella is considered a liquid.
