What Is Hemp Fiber? Processing, Properties and Uses

What hemp fiber is

Hemp fiber is the bast fiber from the stalk of the hemp plant, Cannabis sativa L. It grows as a layer between the outer skin of the stalk and the woody core.

A hemp stalk gives two different raw materials:

• Bast fiber: the long, strong outer fibers. A review chapter by Sunny and Pickering (2021) puts it at about 25-30% of the stem’s dry weight.
• Hurd (also called shiv or shives): the short woody core. The same review puts it at about 65-70% of the stem’s weight.

The split is not fixed. In a 2023 University of Vermont Extension trial, reported through SARE, bast made up 38.6% of the stalk when the crop was cut 74 days after planting, and 22.5-25.6% at later cuts. One variety in the same trial had only 11.2% bast.

Fiber hemp is one of four crop types tracked by USDA. The others are grain, seed and floral hemp. The industrial hemp guide covers all four.

How hemp fiber is processed

Hemp fiber is processed in two main steps: retting, then decortication.

Retting

Retting loosens the fiber from the core. USDA’s National Hemp Report defines it as “a process involving the use of moisture and microbes to break down the chemical bonds (pectin) holding the hemp stem together, enabling easier separation of the bast from the woody core.”

The common method is field retting, also called dew retting. The cut stalks lie on the ground and soil microbes do the work. The University of Vermont Extension field retting guide gives these practical points:

• Field retting in the Northeast generally takes 16-28 days.
• Stalks are flipped roughly every six days, more often after rain.
• The “snap test” shows progress. On a well-retted stalk, the hurd falls away in small chips and the bast bends without breaking.
• Once stalks dry to 15% moisture, retting stops and the crop can be baled.
• Over-retted fiber is weaker and shorter. It can still suit some industrial uses, but not spinning.

USDA estimates that 54.7 million pounds of the 2025 US fiber crop were retted.

Decortication

Decortication is the mechanical separation of bast fiber from hurd. Montana processor IND HEMP says it decorticates hemp straw to separate the bast fiber from the hurd, which it also calls shives.

Output depends on the crop and the machine. Machinery maker Tatham told Textile World that its lines have a maximum potential yield of 300 kg of fiber and 600 kg of shiv per 1,000 kg of stalk.

After decortication, fiber can be cleaned and refined further. IND HEMP lists decorticated technical fiber in bales, refined and “cottonized” fiber, and hurd in several particle sizes.

Properties of hemp fiber

Hemp fiber is strong and stiff for its weight. The figures below come from Tables 1 and 2 of Sunny and Pickering (2021), a peer-reviewed open-access chapter on hemp fiber composites.

Two things stand out. Hemp is weaker than glass fiber in absolute terms. But per unit of weight it is stiffer, which is why it is used as a reinforcement in composites.

These are ranges, not guarantees. Published values vary with the variety, the retting, the test method and the size of the fiber bundle tested.

What hemp fiber is used for

Hemp fiber goes mostly into textiles and industrial materials. The Congressional Research Service report Hemp as an Agricultural Commodity lists these fiber uses:

• Textiles: fabrics, yarns and spun fibers.
• Paper.
• Composites: hemp plastics and composites, described as an alternative to fiberglass in automotive and aviation parts.
• Construction and insulation materials.
• Carpeting and home furnishings.
• Rope: the report names rope among legal hemp products.

The woody hurd has its own markets. CRS lists animal bedding as a hurd use. Hurd is also the plant part mixed with lime to make hempcrete; see US hempcrete companies.

Insulation is one fiber product made in the US today. Hempitecture in Jerome, Idaho lists HempWool insulation batts, FiberFill blown-in insulation and FiberPad carpet underlayment.

US hemp fiber production

The US harvested 21,693 acres of fiber hemp in 2025, according to the USDA NASS National Hemp Report released April 16, 2026. That report is the latest available and covers the 2025 crop year.

Fiber is the largest hemp category by harvested area and the second-smallest of the four open-field categories by value. It took about half of all open-field hemp acres harvested in 2025 (43,707), but about 2% of the $739 million total crop value.

Fiber hemp by state, 2025

USDA publishes only five states. The rest are withheld to avoid disclosing data for individual operations and are grouped as “other states.”

Yields differ a lot between states. USDA reports 7,570 lb per acre in Kansas and 950 lb per acre in Texas for 2025.

Next step

For the legal definition, licensing and all four crop types, read the industrial hemp guide. For the UK picture, see hemp fibre in the UK.