Where does beef usually spoil first?

Beef typically spoils first on the surface due to several factors related to exposure and microbe activity. The surface of the meat is most susceptible to spoilage because it is exposed to the environment, which includes bacteria, molds, and yeasts. These microorganisms can thrive on the outer layer, especially if the meat is not properly stored or handled.

Oxygen is another significant factor; the surface of the meat is exposed to air, promoting the growth of aerobic bacteria that can lead to spoilage. Additionally, the surface is where the meat interacts with other potential contaminants during handling and storage.

While the inner portions and areas near bones can also be prone to spoilage, they are generally less affected until the surface has deteriorated. The edges may spoil due to exposure, but they do not typically experience spoilage before the surface. Thus, the reasoning behind surface spoilage encompasses microbial activity, environmental factors, and the conditions of meat storage and exposure.