What Exactly is Bone Char?
Bone char, sometimes referred to as 'natural carbon' or 'bone black,' is a granular, porous black substance created by charring the bones of cattle at high temperatures (up to 700°C) in an oxygen-deprived vessel. The process removes most organic material, leaving behind a unique form of carbon blended with a calcium phosphate mineral called hydroxyapatite. It is this specific chemical makeup that gives bone char its powerful decolorizing and filtering properties, particularly effective in removing certain impurities and color compounds from liquids.
The Role of Bone Char in Cane Sugar Processing
Raw sugar extracted from sugarcane naturally contains a brownish hue and impurities. To produce the pristine, white granulated sugar many consumers expect, this raw sugar liquor must undergo a decolorization and purification process. This is where bone char comes in. The raw sugar liquid is passed through large beds of bone char filters. Through a process of adsorption, the undesirable coloring components, and some inorganic impurities like sulfates and mineral ions, stick to the surface of the bone char particles. The result is a clearer, less colored liquid that is then further processed into the white crystals we recognize.
It is crucial to note that the bone char itself does not become a part of the final sugar product. It is simply a processing agent, a tool used in one step of a multi-stage manufacturing process. However, for ethical reasons related to the use of animal products, this is a point of contention for many vegans and vegetarians.
The Source and Regulation of Bone Char
For bone char used in sugar refining, the animal bones typically come from cattle sourced from countries like Afghanistan, Argentina, India, and Pakistan. These bones are heavily regulated to prevent the spread of diseases like BSE (Bovine Spongiform Encephalopathy), often referred to as 'mad cow disease'. Only bones from countries deemed BSE-free by regulatory bodies like the USDA are permitted for use in the refining process. Once collected, the bones are dried and then incinerated under controlled conditions to produce the black, granular filtering material.
Alternatives to Bone Char Filtration
As consumer awareness grows and ethical concerns become more prominent, many sugar manufacturers are moving away from bone char. Here are some of the primary alternatives:
- Granular Activated Carbon (GAC): Made from non-animal sources like wood, coal, or coconut husks, GAC is a common and effective alternative for decolorization. It has a very high surface area, which allows it to efficiently adsorb impurities, much like bone char.
- Ion-Exchange Resins: These are synthetic polymer resins that can filter out charged molecules, including impurities and coloring agents, from the sugar solution. This chemical filtration method is also used to purify beet sugar, which is inherently vegan.
- Other Refined Sugars: Some sugars, like those derived from beets, are inherently white and do not require the extensive decolorization process that employs bone char. Therefore, beet sugar is always a vegan option.
- Raw and Unrefined Sugars: Sugars like turbinado, muscovado, and demerara skip the intensive refining step and retain their natural color and molasses content, meaning they are not filtered with bone char.
Comparison of Refined Sugar Filtering Methods
| Feature | Bone Char Filtration | Activated Carbon (GAC) Filtration | Ion-Exchange Resins |
|---|---|---|---|
| Source Material | Charred cattle bones | Non-animal sources (e.g., coconut shells) | Synthetic polymers |
| Vegan Status | Not considered vegan | Vegan-friendly | Vegan-friendly |
| Mechanism | Adsorption (attraction of colorants to porous surface) | Adsorption (attraction of impurities to high-surface-area carbon) | Ion exchange (separation based on electrical charge) |
| Primary Use | Decolorizing cane sugar | Decolorizing and purifying various liquids | Purifying sugar solutions and water |
| Availability | Still used by some cane sugar refiners | Widely used across the food industry | Common in modern sugar refining |
Is it Bone Char or Bone Ash?
It is important to differentiate between these two terms. Bone char is the black, porous material used for filtration, created by heating bones in a low-oxygen environment. Bone ash, on the other hand, is the result of heating bones in an oxygen-rich atmosphere, resulting in a different chemical makeup. Bone char's unique composition is what makes it effective for sugar decolorization, and the two cannot be used interchangeably for this purpose.
Conclusion
Understanding what is bone char in sugar production reveals a nuance in food manufacturing that can be particularly relevant for those with dietary restrictions or ethical concerns. While the final refined sugar product does not contain actual bone particles, the use of a filter derived from animal remains is a determining factor for vegans and some vegetarians when making purchasing decisions. Fortunately, the rise of conscious consumerism has led to a wider availability of vegan-friendly options, from organic cane sugar that uses plant-based activated carbon to readily available beet sugar that requires no animal-based filtration at all. By checking labels for 'certified organic' or 'beet sugar,' consumers can make informed choices that align with their ethical principles.
Further Reading
For more information on the processing of sugar and its impact on dietary choices, consider visiting the Plant Based News article on the vegan status of sugar.
