December 12, 2014

arabica coffee or not

We recently had a discussion at Apug if pure arabica coffee without Vit-C would do any development, one guy reported that he had no development at all with arabica coffee. We can read at different places that the cheap and awful robusta would be the best for developing film and arabica would be worse, but no development at all? Furthermore, I didn't have single report here on my blog of any failure caused by arabica coffee. Au contraire, people told me that they used 100% arabica "premium" instant coffee, because it was at hand, and got excellent results. I also made such an experiment and could confirm, that pure arabica coffee was not worse than any other I tried so far. But I made the test with Caffenol-C. Now I decided to make a side by side comparison of 100 % arabica and the cheapest instant coffee available here without Vit-C, to get the results from coffee with washing soda alone. To make it worse, I used decaffeinated(!) arabica. Both samples were developed at the same time side by side. To make a simple story simple: I can't distinguish both! They look exactly the same, even held against a lamp for better judgement: identical blackening. To be honest, I wasn't surprised very much. But of course using a more expensive coffee is a waiste of money.

PS: my old flickr buddy Larry aka inetjoker just said that he only once had a failure with caffenol, and it was a deacidified coffee. Again no big surprise, caffeic acid is regarded as the main developing agent of coffee. Thank you so much, Larry for all your help and simply for being around always.


Both developments were made with snippets of Polylan F, I cut off 1 edge for the arabica developement and 2 edges for the "cheap" development for further reference. The recipe for both was:

40 g/l instant coffee and 40 g/l washing soda waterfree, that's it. pH was about 9.9 for both. Fixing and rinsing as usual.

Stand developed 60 minutes at room temp with some stirring every 10 minutes or so. That was a quick and dirty test, everybody can repeat it with a minimum effort.

See you guys, happy developings



Henrique Sousa said...

Yes, Larry is a 'soul'! Eine Seele!

Urban Hafner said...

Thanks for doing this Reinhold. Someone has to hold up the scientific method. :) Too often we just repeat whatever we read somewhere and don't challenge these assumptions.

Bo Sibbern-Larsen said...

I remember reading an article where one guy tried everything from the cheapest to Davidoff instants, with pretty much the same results as yours :) Altho he did claim that the Davidoff instant yielded better contrast and less basefog.. Placebo imo :) Merry Xmas and a Happy New Year to you Reinhold!


imagesfrugales said...

This is a nice gathering of friends. Thank you very much Bo, and of course best wishes for everybody.

Erazm said...

Hi Reinhold!
Do you have access to some pro pH meter or you're using some cheap "made in china" device?
I'm wondering, how inaccurate are these cheap devices. I have one, and it gives me reading of ~9.6 for C-C-L...

imagesfrugales said...

Hi Erasm, I have a cheap one but it gives me consistant and imo reasonable (pH 7 for plain water)readings since about 3 years. I know they are not very precise, maybe I had luck. But I can't guarantee for accuracy.

The dry electrodes degrade until they are kaputt. Again I had luck so far, I don't store it in a KCl solution as recommended. Before reading I soak it in tap water with some grains of kitchen salt for some minutes until the reading is stable. Also the temperature should be close to 20 °C.

To be sure about the readings you may buy calibration solutions e.g. from an aquarium shop. I never did that.

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