Oils such as sunflower, corn and rice bran contain waxes that cause cloudiness when the oil is chilled. Winterisation (dewaxing) removes these waxes to produce a bright, clear oil. While bleaching and dewaxing are separate steps, they interact. This guide explains how.
Why Oils Turn Cloudy
Natural waxes — long-chain esters — are soluble in warm oil but crystallise when the oil cools, producing haze or sediment. Winterisation chills the oil so waxes crystallise, then filters them out, giving an oil that stays clear in cold storage or on a supermarket shelf in winter.
How Bleaching Supports Dewaxing
Bleaching removes colour bodies, phospholipids, soaps and trace metals. A cleaner bleached oil produces more uniform wax crystals during winterisation and filters more cleanly, improving dewaxing efficiency and the clarity of the final oil.
Sequence in the Refinery
Depending on the process, dewaxing may occur before or after bleaching, or be integrated with it. In some configurations bleaching earth is present during the chilling/filtration step, helping capture impurities alongside the wax.
Oils That Need Dewaxing
Sunflower, corn, rice bran and some grades of other oils are the usual candidates. Rice bran oil in particular carries significant wax and benefits from careful integration of bleaching and dewaxing.
Clean Bleaching for Clear Oil
A consistent, high-activity bleaching earth like Bleach Master delivers the clean, low-impurity oil that makes downstream dewaxing reliable and the final product brilliantly clear.
Frequently Asked Questions
What is winterisation/dewaxing?
Chilling an oil so its natural waxes crystallise, then filtering them out, so the oil stays clear when cold. It is used for oils like sunflower, corn and rice bran.
Does bleaching remove waxes?
No — wax removal is the job of winterisation/dewaxing. But clean bleached oil (free of phospholipids, soaps and metals) produces more uniform wax crystals and filters more cleanly during dewaxing.
Which oils need dewaxing?
Commonly sunflower, corn and rice bran oil, which carry waxes that cause cloudiness when chilled. Rice bran oil in particular benefits from careful bleaching-plus-dewaxing integration.
Does the order of bleaching and dewaxing matter?
It depends on the process configuration; dewaxing may occur before, after or integrated with bleaching. In some setups bleaching earth is present during chilling/filtration to capture impurities alongside the wax.
Need Activated Bleaching Earth for Your Refinery?
Contact Umiya Minerals for product samples, technical data sheets, and bulk pricing. We supply pan-India from Bhuj, Gujarat.