Thanks (again) for posting such an interesting question, and for
directing it my way. Sorry it took me a while to post an answer, but
I think you'll be pleased with the results.
As I mentioned earlier, bone ash is, indeed, used as a filtering agent
in the production of at least some sugar. I'm providing here an
overview of the topic, along with information to address the specific
questions you asked.
As always, if you find you would like any additional information, just
let me know, and I'll be happy to do some more research on this.
First, a bit of terminology and definition. Bone ash goes by several
different names. It is sometimes called boneblack or bone-black, bone
charcoal, bone char, animal black, animal charcoal, and similar sorts
A related term that it pays to be familiar with is "activated
charcoal", since bone ash belongs to this category of highly-absorbent
carbon material used as a filtering agent for many different types of
A list of definitions, synonyms, etc. can be seen here:
The Wikipedia definition calls for particular attention:
Bone char, also known as bone black or animal charcoal, is a granular
black material produced by calcining animal bones: the bones are
heated to high temperatures in the absence of air to drive off
volatile substances. It consists mainly of calcium phosphate and a
small amount of carbon. Bone char has a very high surface area and a
high absorptive capacity for lead, mercury, and arsenic.
Bone char is used to remove fluoride from water and to filter aquarium
water. It has been used in the sugar refining industry for
decolorizing (a process patented by Louis Constant in 1812 which is no
longer commonly used).
From the information at the above link, its clear that:
--bone ash is produced from animal bones heated to a very high
temperature. The result is a product that bears little resemblance to
the original bone (just as charcoal or fireplace ash bears little
resemblance the material originally burned).
--bone ash is generally associated with sugar refining
--the use of bone ash as a filter agent for sugar has been around for
quite a while, and was patented in 1812.
The wikipedia definition also notes that, although the use of bone
black was a common process in the sugar industry at one time, it is
less so today. However, several other sources of information lead me
to believe this is simply not the case, and that the practice is still
fairly common in the modern sugar industry.
For instance, an interesting history of the discovery and commercial
development of the bone black industry can be found at the Ebonex
company site...Ebonex still manufactures bone black as a pigment. The
history is provided at these two links:
Note that Ebonex states:
"Today, bone charcoal is still the prime adsorbent used in the sugar
So, there's a bit of a discrepancy between the Wikipedia site and the
Ebonex site, but given the fact that Ebonex is in the bone black
business, I'm more inclined to accept their version. In fact, the
information from this next site certainly suggests that use of bone
ash for sugar refining is still in widespread use.
The site in question is a vegan (strict vegetarian) discussion site
devoted to the topic of sugar:
Veganism & Processed Sugar
Here's the issue: Some processed sugar is filtered with charred bone.
Does that mean that vegans must avoid all processed sugar? Some say
yes, some say not necessarily....
We recently contacted C & H Sugar Company, which is one of the world's
largest manufacturers. This was their response, dated February 25,
Thank you for taking the time to contact C & H Sugar regarding our use
of carbonized bone charcoal. There are no animal products in the sugar
itself, which is certified kosher. Bone char is made from cattle bones
only, never from those of other animals. The function of the bone char
is to remove impurities from raw sugar.
The bones used are not the byproducts of the meat packing industries,
but are from cattle that have died naturally, in places like India,
Pakistan and Nigeria. The principal use for such bone material is for
gelatin production, and charcoal manufacture is a by-product of this
industry. In Scotland, they are burned in an enclosed atmosphere, at
1200º centigrade, to create activated charcoal. This bone charcoal is
used to remove color, impurities, and certain naturally occurring
minerals that could result in cloudiness when the sugar is dissolved.
The bone char is not "in" the sugar, but is used only as a filter,
similar to a coffee filter. Its use is a very common practice in sugar
refining, and is currently the best available. Vegetable charcoal does
not remove ash, so sugar produced using this type of carbon as an
alternative is likely to be of somewhat lower quality. C&H Sugar is
looking for alternatives. If a consumer finds the use of this bone
charcoal objectionable, an alternative would be a specialty sugar. C&H
Hawaiian Washed Raw is processed in the Hawaiian Islands, where lime
(calcium carbonate) is used a s a clarifying agent, rather than
carbonized bone char. It is then transported to our Mainland refinery,
where it is dried and packaged. It should be available in markets that
carry C&H Sugar.
So, the excerpt from the C&H Sugar Company adds a lot of useful information:
--bone ash (also called bone char) is made only from cattle bones --
no other animals -- and only from animals that have died naturally.
--the bones are burned at high heat to produce an activated-carbon form of charcoal
--sugar is filtered through the bone ash, hence it comes directly in
contact with the material
--use of bone ash in the sugar industry is reportedly "very common"
--filter substrates made from non-animal materials are not considered
to perform as well as bone ash, at least as far as decolorizing sugar
Other vegan sites carry on similar discussions, and some of them
provide useful additional information:
The Great Sugar Debate: Is it vegan?
Bone char, made from the bones of cows, is at times used to whiten
sugar. Some sugar companies use it in filters to decolorize their
sugar. Other types of filters involve granular carbon or an ion
exchange system rather than bone char.
The following sugar companies DO NOT use bone-char filters:
Florida Crystals Refinery
Labels: Florida Crystals
Refined Sugars Incorporated
Labels: Jack Frost, Country Cane, 4# Flow-Sweet
Makes powdered brown sugar
Supreme Sugar Company
Labels: Supreme, Southern Bell, Rouse's Markets
The following sugar companies DO use bone-char filters:
California & Hawaiian Sugar Company
Supermarket brands of sugar (e.g., Giant, Townhouse, etc.) buy their
sugar from several different refineries, so there is no way of knowing
whether it is vegan at any given time.
...If you want to avoid all refined sugars, we recommend alternatives
such as Sucanat and turbinado sugar. Neither of these sweeteners are
ever filtered with bone char. Additionally, beet sugar--though
normally refined--never involves the use of bone char.
Again, this list seems to confirm that the use of bone ash in the
sugar industry is widespread, but not universal.
Another fairly detailed vegan-inspired article can be found here:
It adds some additional information about how each of the various
sugar companies use -- or avoid -- bone ash, and also discusses the
differences between cane sugar and beet sugar, in case this is of
interest to you.
A little historical wrinkle can be found at the Sugar Processing
Research Institute website, which discusses the history of (believe it
or not) the Bone Char Research Project:
The Sugar Processing Research Institute, Inc. has developed from two
preceding research organizations. In the late 1930's there was concern
on the part of some cane sugar refiners in the U.S. that their
refining process depended on bone char, a substance about which little
was known. A group of sugar refiners was brought together by John W.
Lowe of Revere Sugar to support research on bone char at the National
Bureau of Standards, Washington, D.C., where Frederick J. Bates worked
with the sugar industry on polarimetry. In 1939, Dr. Victor R. Deitz
initiated the work of the Bone Char Research Project (BCRP), on the
nature and reactions of bone char and other decolorizing carbons. In
1948, Dr. Frank G. Carpenter and Neil Pennington joined the BCRP
Director, Dr. Deitz, and investigations expanded into the chemistry
and processing of other areas of cane sugar refining. The BCRP Reports
and Proceedings of the seven Technical Sessions on Bone Char are still
the major source of information on decolorizing carbons in sugar
Lastly, you asked whether water filters such as the Brita filter use
bone ash filter materials. I'm almost certain the answer is no,
--bone ash is used for sugar refining to remove large quantities of
gross contaminants, primarily to decolorize the sugar. No such
similar step would be needed to filter water, which is relatively pure
and uncolored to begin with.
--companies wouldn't risk using bone ash in their home water filter
products due to the high "Ewwww!" factor if the public were to become
aware of its use.
Water filters typically DO use activated carbon filters as part of
their filtration process. However, activated carbon can be obtained
from vegetable and mineral sources, as well as from animal bones, so
that there is no incentive that I can see for water filtration
companies to use animal-based products.
I trust this information fully answers your question. However, before
rating this answer, please let me know if there is anything else I can
do for you. Just post a Request for Clarification, and I'm at your
All the best,
search strategy -- Google search on:
[ sugar filter (bone ash OR boneblack OR bone char) ]
Clarification of Answer by
22 Feb 2005 17:04 PST
Whew! You obviously have an active, curious mind. Thanks for making
me part of the discovery process on this topic.
If you don't mind, I'm going to focus my follow-up comments on bone
ash and sugar.
I know you are also quite keen to know more about filtration at
drinking water treatment plants, and whether bone ash is used, and how
this affects fluoride. If I may make a suggestion, this is probably
best left to a separate question, as it travels quite far afield from
your original question here. However, you are certainly welcome to
post another question (or questions) on this topic, if you would like
a researcher to delve into it further.
As for bone ash and sugar, let me add a bit of information:
--just to reiterate an earlier point, the water isn't being filtered
through anything resembling bone. The bone has been heated at a very
high temperature, burned, and is more like crushed charcoal than not.
--the sugar is in the form of a liquid slurry when it comes in contact
with the bone ash for filtration. Basically it is poured through a
colum of bone ash, and therefore the sugar comes into direct contact
with the sugar slurry. As the sugar slurry passes through the filter
colums, most of the undesirable color is removed.
--You asked about "remnants" of the bone ask in sugar. Several of the
sites I mentioned earlier made the point that there isn't any actual
bone ash in the sugar. For instance, the material from C&H sugar
stated that: "...The bone char is not "in" the sugar, but is used
only as a filter, similar to a coffee filter...". If I can offer an
interpretation here, this means that no bulk quantities of bone ash
are present in the sugar. However, it seems inevitable that
microscopic quantities would, in fact, be carried along with the sugar
slurry and appear in the final product. Again, though, I would expect
these amounts to be miniscule, and perhaps even undetectable. I am
not aware of any sites that report on the actual presence of bone ash
remnants in sugar, though.
Finally, let me say just a bit about fluoridation, based on my own
knowledge. Small amounts of fluoride are added to drinking water as
protection against tooth decay. This fluoride is still present in the
tap water you drink (if your local water system is fluoridated, that
is). Some types of water filters (whether from bone ash or from
another source) can remove fluorides from water. But I imagine that
in systems that want the fluoride to be present, the water is filtered
BEFORE the fluoride is added, so as not to remove it.
That's my take on things. I hope this additional information helps
you get a fuller picture of the use of bone ash in sugar processing.
All the best,