Winterization of oil is a process that uses a solvent and cold temperatures to separate lipids and other desired oil compounds from waxes. Winterization is a type of fractionation (also known as fractionate crystallization), the general process of separating the triglycerides found in fats and oils, using the difference in their melting points, solubility, and volatility. Winterization is an oil refinement technique commonly used in biotechnology. The process involves dissolving the extract in ethanol, then placing the mixture in a freezer to chill. The cold allows for the separation of compounds by differences in their melting and precipitation points. In the cooling process, the fats and waxes with higher melting points will precipitate out and can then be removed by

filtration Filtration is a physical separation process that separates solid matter and fluid from a mixture using a ''filter medium'' that has a complex structure through which only the fluid can pass. Solid particles that cannot pass through the filter ...

centrifugation Centrifugation is a mechanical process which involves the use of the centrifugal force to separate particles from a solution according to their size, shape, density, medium viscosity and rotor speed. The denser components of the mixture migrate ...

, decantation, or other separation processes. A pure, liquid oil extract is left behind, ready to be further processed for consumer use.

Bioindustry applications

Food products containing non-processed oils, such as fats and waxes with higher melting points, will crystallize in refrigeration temperatures. This precipitation could result in products like salad dressings separating during cold storage. Winterization is used to refine oil in salad dressings,

mayonnaise Mayonnaise (; ), colloquially referred to as "mayo" , is a thick, cold, and creamy sauce or dressing commonly used on sandwiches, hamburgers, composed salads, and French fries. It also forms the base for various other sauces, such as tartar ...

, cooking oils like

sunflower oil Sunflower oil is the non-volatile oil pressed from the seeds of the sunflower (''Helianthus annuus''). Sunflower oil is commonly used in food as a frying oil, and in cosmetic formulations as an emollient. Sunflower oil is primarily composed ...

, and botanical oils. Rice bran oil is one of the most commonly winterized oils, as it has a high content of waxes, fatty acids and lipids. Winterization is also used in refining

biofuel Biofuel is a fuel that is produced over a short time span from biomass, rather than by the very slow natural processes involved in the formation of fossil fuels, such as oil. According to the United States Energy Information Administration (E ...

, as it improves low temperature flow properties. This is necessary in preventing

crystallization Crystallization is the process by which solid forms, where the atoms or molecules are highly organized into a structure known as a crystal. Some ways by which crystals form are precipitating from a solution, freezing, or more rarely deposi ...

of certain compounds in the fuel, which could cause problems with compression engines. Winterization is also a common process in the cannabis industry, used to remove unwanted compounds from cannabis oil extracts. Winterization often follows supercritical CO₂

extraction Extraction may refer to: Science and technology Biology and medicine * Comedo extraction, a method of acne treatment * Dental extraction, the surgical removal of a tooth from the mouth Computing and information science * Data extraction, the pro ...

, for the production of cannabis oils to be used in vape pens and capsules.

References

Oil refining {{Chem-stub