[Sca-cooks] chemical leavening

[Johnna Holloway]

I came across this description last evening:

The horns of the deer, or Hartshorn, have been medical from time 
immemorial. The shavings or raspings, boiled for a long time in water, 
produce a considerable proportion of Hartshorn-Jelly, which is of a 
nourishing quality. By distillation, an ammoniacal liquor is procured, 
which, freed from its oil and rendered limpid by successive 
distillations, is commonly called Spirit Of Hartshorn. It is a Carbonate 
of Ammonia dissolved in water which, when saturated, deposits the 
Carbonate in the form of a salt usually termed Salt Of Hartshorn, or 
Volatile Salts. By continuing the heat, the Hartshorn is calcined and 
wholly converted into Phosphate of Lime, which is ground into a white 
powder, and, in various mixtures, is prescribed as a medicine. These 
different preparations are also made with common bones, which, unless in 
their containing a less proportion of gelatine, do not differ in their 
constituent principles from Hartshorn.

An Analytical Dictionary of the English Language, in which the Words are 
Explained in the Order of Their Natural Affinity, Independent of 
Alphabetical Arrangement ...By David Booth

Published by Simpkin, Marshall, 1836

Johnnae


Master A wrote:
>> OK, but if we're looking at the alkaloid properties of bone, why use 
>> horn? Does processed horn include the bone, or just the proteinaceous 
>> outer layer? -- I thought the latter. If the natural descendant of 
>> the process is ammonium carbonate, you'd need that nitrogen atom, 
>> right,  and if it's coming from an animal, doesn't that suggest 
>> protein,  collagen, keratin, that sort of thing?
>>
>> How do you get CO2 or another leavening gas directly from protein? I 
>> think the answer is you don't, that you have to turn it into ash and 
>> distill from that an ammonia salt.
>>
> Bear wrote:
> The critical component of the ammonium carbonate is the CO3 molecule 
> which releases CO2 when broken down with a weak acid.
>
> I did a quick search for the chemical composition of antler and came 
> up with this:  
> http://www.deertracking.com/library/aug2002_antlers3.html .  From what 
> I see there would be nothing that would react in the appropriate 
> manner in unmodified antler.  Your suggestion about burning the bone 
> makes a great deal of sense.  Burning the bone and leaching the ashes 
> should produce a form of potash, of which potassium hydroxide would be 
> the most reactive leavening.
>