Which factor does NOT affect a consumer's perception of a beer's body?

The perception of a beer’s body is influenced by several key factors that contribute to its overall mouthfeel and texture. Alcohol content plays a role because higher alcohol levels can lead to a fuller body, as alcohol adds viscosity. The grain bill, which includes the types and amounts of malts used, significantly impacts body as different grains contribute varying levels of unfermentable sugars and proteins, affecting mouthfeel and richness. Mash temperature during the brewing process also influences body; higher mash temperatures can lead to a thicker body due to the production of more unfermentable sugars.

In contrast, fermentation time does not directly affect a consumer's perception of a beer’s body. While fermentation time can influence overall flavor, carbonation, and clarity, it does not inherently change the residual sweetness or texture components that are primary determinants of body. Thus, this factor is the one that does not contribute significantly to the perception of body in a beer.