Definition - What does Pulp mean?
The pulp is the part of a grape's anatomy where the juice is contained. It is located in the center and surrounds and protects the seed (also called "pip"). The pulp is contained by a layer of skin. This skin may have various characteristics and may be thick or thin, which can give both color and structure to a grape's pulp and determines flavor, tannin and color in a finished wine.
WineFrog explains Pulp
The pulp is the section of a grape where juice is contained. It surrounds and protects the seed, and the pulp is protected by the skin of the grape. The pulp is made up of 70 to 80% water where many dissolved solids can be found; both organic and inorganic.
The pulp contains sugars, organic acids, phenolic compounds, nitrogenous compounds, aroma compounds, minerals and pectic substances.
Many of these soluble compounds are key elements which later give certain taste, aroma and structural characteristics to a wine from the grapes' pressed juices. The skin, which surrounds the pulp, also plays a role in the characteristics of pulp, sometimes adding color, but mostly adding texture, such as tannic acid. In more rugged terms, the pulp can be described as the "meat" or "flesh" of the grape.