Coffee Developers - Why do they Work?

[laverdure]

Urine will only develop film if it contains hydroquinone, which can happen due to certain illnesses, or if you ingest the herb uva ursi (coincidentally a great cure for urinary tract infection (I'm not kidding)).

When I was playing around with coffee last year, my more organic chemistry minded friend came to believe it was the phenols which were the primary developing agent. Based on that assumption, we got mint, thyme, and basil to work, before we read elsewhere that it'd been done. I was just messing around, but I hear that mint works much better than coffee. Has anyone actually used wine?

oh, don't know if it's been answered, but the reason people use instant coffee is because the measurements are easier to standardize.

 

[rwyoung]

I do believe it is the caffeic acid that is doing the majority of the work. Caffeic acid is a phenol and is relatively similar to catechol and hydroquinone but with a few extra bits and its OH pairs aligned a little bit differently. Coffee in general is quite a witches brew of phenols!

I think caffeic acid is still present in decaf coffee, need to get a small jar of instant decaf and try it.

 

[Jordan]

There are only three possible configurations of dihydroxybenzene: 1,2-dihydroxybenzene (catechol), 1,3 (resorcinol) and 1,4 (hydroquinone). Of these three, only resorcinol is not active as a developing agent (it can't form quinones as the electrons don't "push" the right way). Caffeic acid is in fact a catechol -- its hydroxy groups are in the 1 and 2 positions on the ring -- it also has an acrylic acid substituent elsewhere on the ring that is not terribly photographically active.

I'm thinking of ways to make caffeic acid in the lab, and while it's a somewhat simple molecule, the "hookup" of its structure would make it take a couple of steps -- hence the price.

 

[Alex Bishop-Thorpe]

All of this is making me wish I'd taken chemistry in highschool. And reaffirmed my decision to ditch the coffee...Very interesting though.

 

[Steve Smith]

I suppose that if I were really desperate at some point in the future and couldn't obtain any normal developing agent, it could be tweaked enough to be something like ABC pyro.

I tried Caffenol once and thought it was quite good. I would definitely use it again if I had run out of 'proper' developer and wanted to process a film quickly.

I was pleased to find a practical use for coffee. I can't bring myself to drink the horrible stuff!

Steve.

 

[hywel]

More on the Wine Please...

Perhpas because I'm a tea-drinking Brit coffee really doesn't excite me. But the idea of developing in red wine is so outragous that, if it can be done, I have a sudden urge (no doubt in part due to the wine I've just drunk) to try it. So can it really be done, has anyone done it, should I add some washing soda? Anyone help me start? I have a third of a bottle of wine sitting beside me that my liver would thank me for not finishing...

Hywel

 

[titrisol]

I think that experiment was already done, search in the archives during the winter of 2004

Caffeic acid can be horribly expensive yes, that is why is more convenient to use instant caffe!
Mint works great, but you need lots of leaves to make a developer.

Run a google of coffe developer RIT or mint developer RIT

I do believe it is the caffeic acid that is doing the majority of the work. Caffeic acid is a phenol and is relatively similar to catechol and hydroquinone but with a few extra bits and its OH pairs aligned a little bit differently. Coffee in general is quite a witches brew of phenols!

I think caffeic acid is still present in decaf coffee, need to get a small jar of instant decaf and try it.

 

[Dave Swinnard]

Yup, it works.

I tried the caffenol recipe today at a student's request.

HP5+ @ 200 for 35min about 68F (20C) with 10 sec. agitation every minute or so (mostly so, as I kept getting pulled away to attend other things...)

Image is certainly present but is heavily stained, low contrast but with adequate shadow details. I hope to try and print it tonight.

Maxwell House instant and a "super" washing soda with the Arm & Hammer logo. (I think "super" means it had something a bit "perfumed" in it.)

Cool

Dave

 

[Tom Hoskinson]

There are only three possible configurations of dihydroxybenzene: 1,2-dihydroxybenzene (catechol), 1,3 (resorcinol) and 1,4 (hydroquinone). Of these three, only resorcinol is not active as a developing agent (it can't form quinones as the electrons don't "push" the right way). Caffeic acid is in fact a catechol -- its hydroxy groups are in the 1 and 2 positions on the ring -- it also has an acrylic acid substituent elsewhere on the ring that is not terribly photographically active.

I'm thinking of ways to make caffeic acid in the lab, and while it's a somewhat simple molecule, the "hookup" of its structure would make it take a couple of steps -- hence the price.

I've read that coffee (both instant and brewed) contains both caffeic acid and oxalic acid. Oxalic acid has a long history as a developing agent. I wonder if anyone has done comparative testing? Maybe Folgers Instant vs Starbucks brewed?

 

[David A. Goldfarb]

Yes, if you go to the paper I linked above, it says what the concentration of Oxalic acid is as well.

 

[Tom Hoskinson]

Yes, if you go to the paper I linked above, it says what the concentration of Oxalic acid is as well.

Yes David, your link is the reference I had in mind.

 

[pedropolis]

developing with mint, thyme, and basil

When I was playing around with coffee last year, my more organic chemistry minded friend came to believe it was the phenols which were the primary developing agent. Based on that assumption, we got mint, thyme, and basil to work, before we read elsewhere that it'd been done. I was just messing around, but I hear that mint works much better than coffee.

Hi laverdure, those sound like good experiments, can you please post details on how you used the mint?

did you arrive at a formula that worked well? or can you give any starting points?

cheers

pete