Viscosity

The resistance of a material to flow, determining how easily it moves, pours, transfers and fills.

Synonyms: Flow resistance, fluid thickness, how runny something is

Last updated: 5 September 2026

Viscosity describes how strongly a material resists flowing. A highly viscous cannabinoid is thick and moves slowly, while a material with lower viscosity flows more easily.

Many cannabinoid distillates are naturally highly viscous, particularly at lower temperatures. This is why the same material can appear almost solid or extremely thick when cold, yet become considerably more fluid when warmed.

Viscosity is important during weighing, mixing, transfer, filling and storage because it directly influences how easily cannabinoid material moves through equipment and how the finished formulation behaves in its intended application.

Viscosity can affect:

Transfer speed Highly viscous materials move more slowly between containers and through narrow openings.

Residue Thicker material is generally more likely to remain attached to equipment and container surfaces.

Filling Viscosity influences how easily bottles, syringes, cartridges and other containers can be filled.

Mixing Highly viscous components can require more time to distribute uniformly throughout a formulation.

Hardware compatibility A formulation that is too thick or too fluid for its intended hardware may not flow or perform as expected.

Final product behaviour The finished formulation should have flow characteristics that match the intended use, packaging and expected product behaviour.

Visual example

High viscosity vs low viscosity

High-viscosity material resists movement and flows slowly, while lower-viscosity material flows more freely.

High viscosity Thick material with strong resistance to flow and a greater tendency to remain on surfaces.

Flow

Slow

Low viscosity More fluid material with lower resistance to flow and easier movement through equipment.

Flow

Faster

Lower temperature Generally higher viscosity

→

Higher temperature Generally lower viscosity

For many cannabinoid distillates, increasing temperature substantially lowers viscosity. The exact relationship depends on the cannabinoid and complete formulation.

What influences cannabinoid viscosity?

Temperature

Temperature is one of the most noticeable influences on cannabinoid viscosity. Many cannabinoid distillates become progressively more fluid as temperature increases and considerably thicker as they cool.

This is why the same cannabinoid can behave very differently during cold storage compared with handling at a warmer temperature.

Lower viscosity can make handling easier, but the suitable temperature range of the cannabinoid or complete formulation should always be respected.

Cannabinoid composition

Different cannabinoids have different physical properties. A formulation rich in one cannabinoid can therefore have a noticeably different viscosity from one containing another cannabinoid, even at the same temperature.

Purity and the presence of other naturally occurring or residual components can also influence the physical behaviour of the material.

Other formulation ingredients

Carrier oils, terpenes and other formulation components can change the flow behaviour of a cannabinoid mixture. Adding a lower-viscosity component can reduce the overall viscosity of the final formulation.

The effect depends on both the ingredients and their proportions, which means viscosity cannot reliably be predicted from cannabinoid concentration alone.

The target viscosity should ultimately match the intended final product. A formulation designed for a cartridge, tincture, syringe or bulk container may require very different flow characteristics to behave as expected.

Crystallisation and physical state

Crystallisation can substantially change how a cannabinoid material flows. A formulation that begins forming crystals may become progressively thicker, less uniform or eventually stop behaving like a freely flowing liquid.

These physical changes are not always immediate. Crystal formation, crystal dissolution and other changes in physical state can require time, even after the temperature of the material has already changed.

A formulation may therefore continue changing after warming or cooling rather than reaching its final physical behaviour as soon as a new temperature is reached.

Observed thickness can reflect both true liquid viscosity and changes in physical state such as crystallisation.

Temperature equilibration

The temperature of the surrounding room, refrigerator or heating environment is not necessarily the temperature of the cannabinoid itself. Larger quantities in particular can take time to reach a new temperature throughout the complete material.

Viscosity can therefore continue changing while the cannabinoid gradually approaches thermal equilibrium.