Coffeehound
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The addition of ascorbic acid creates an additive type developer.
You sure? I thought that people who know more than I (of which there are a heck of a lot) had concluded it was probably superadditive. I may, however, be wrong.
-NT
I fail to see the fascination that some people have for it.
I fail to see the fascination that some people have for it.
For superadditivity one developing agent must be of the Pelz type HO-(C=C)n-OH and the other of type HO-(C=C)n-NH2. Also included in this latter type are compounds such as HO-(C=N)n-NH2. Both caffeic acid and ascorbic acid are of the former type while metol and phenidone fit the latter type.
The developing agent in coffee is said to be caffeic acid. Unfortunately coffee is a natural product of variable composition. The amount of caffeic acid varies between 35 to 175 mg for a 200 ml cup of coffee. Roasting destroys the caffeic acid and the darker the roast the less caffeic acid. The amount also varies with the type of coffee, robusta beans containing more than arablica beans.
Despite claims to the contrary, there is nothing magicial or miraculous about caffeic acid. It behaves exactly as its parent chemical catechol does as a developing agent. I fail to see the fascination that some people have for it.
I fail to see the fascination that some people have for it
my fascination is that it made of household items
...
and it i have a lot of fun using it ...
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