Overview

Pulp is a general term for a soft, often fibrous mass produced when a solid material is macerated, ground, dissolved or otherwise reduced to a moist or mushy state. The word is used across industries and disciplines to describe raw material for papermaking, the edible flesh of produce, the living tissue inside teeth, and a style of inexpensive popular fiction and magazines.

Pulp in papermaking and industry

In papermaking, pulp is the cellulose-rich material obtained from wood, recycled paper or non-wood plants such as straw or bagasse. Pulping methods are broadly mechanical—physically separating fibers—and chemical—removing lignin and other non-cellulosic components. Mechanical pulps tend to retain more lignin and are darker and weaker, while chemical pulps are stronger and easier to bleach. Pulp is processed into paper, cardboard, tissue and specialty grades and is also an intermediate for cellulose derivatives and some bio-based products.

Environmental and processing considerations

Pulp production intersects with forestry management, water and energy use, and chemical handling. Recycled pulp reduces demand for virgin fiber but may require deinking and cleaning. Alternatives to chlorine bleaching, such as oxygen-based and totally chlorine-free methods, are used to reduce environmental impact. Sustainable sourcing and efficient processing are central concerns in the industry.

Food pulp

In culinary and food-processing contexts, pulp refers to the soft, fleshy part of fruit or vegetables that remains after juicing or the blended mass used in purees, sauces and jams. Fruit pulp contains fiber, pectins and much of the flavor and color of the original produce. In recipes and product labeling the presence or absence of pulp affects texture, mouthfeel and nutritional content.

Dental pulp

Dental pulp is the living connective tissue within a tooth, containing nerves, blood vessels and specialized cells. It occupies the pulp chamber and root canals and is important for tooth development, nutrition and sensation. Injury or infection of this tissue (pulpitis) can cause pain; treatment ranges from protective procedures to root canal therapy or, in some cases, extraction.

Pulp in culture: magazines and fiction

The term "pulp" also describes inexpensive fiction magazines printed on cheap paper made from wood pulp and the fast-paced, sensational stories they carried. These publications were influential in the development of genre fiction—crime, adventure, horror and science fiction—and the phrase "pulp fiction" now denotes lurid or action-driven storytelling and a lasting aesthetic in literature and film.

Common types and distinctions

  • Sources: wood pulp, recycled pulp, and non-wood plant pulps.
  • Processes: mechanical, chemical (kraft, sulfite) and semi-chemical pulps.
  • Food uses: pulp vs clear juice (fiber content) and culinary preparations.
  • Dental terms: healthy pulp, reversible or irreversible pulpitis, endodontic treatment.