ipernity: Group: Caffenol - The Joy of Coffee & Film

Recipe questions

After successfully developing several films in a very simple caffenol recipe:

30g instant coffee granules
16g soda
14g vitamin C
...in 700ml water
16 minutes at 22 degrees C

...I just realised today that I had been using sodium ascorbate (which was sold advertised as vitamin C), rather than ascorbic acid.

When I switched over to using my new supply of pure ascorbic acid, in the same quantity, the results were disappointingly under-developed.

That seems surprising to me - I might have expected the ascorbic acid to perform better.

Can anyone explain the different effects of ascorbate / ascorbic acid in caffenol, and which one is better to use?

Also - has anyone tried using pure caffeine powder, in place of the coffee? Would that work just as well? If so, what kind of quantity, in the recipe above?

Thanks :)

Comments

imagesfrugales

Hi Jim,

sorry that it takes 3 weeks that anybody answers your question. And the answer is very simple. Coffee needs an alkaline solution to be an active developing agent.

If you use ascorbic acid instead of ascorbate, you get a solution that is too acidic. Caffeic acid, the main developing agent, is also very acidic. The ascorbate is more or less neutral. If you change either the amount of caffeic or ascorbic acid, you also have to adjust the amount of the washing soda. You should use about 5 gramms more soda (waterfree!!!) to compensate for the change of ascorbate to ascorbic acid as a raw estimation.

Since you have a lot(!) of acids and not much alkaline soda in the mix I'm not surprised that the modified recipe fails.

It doesn't matter if you use Vit-C or ascorbate as long as you adapt the soda accordingly. Caffeine is no developing agent at all. It's useless for our purpose. It's the caffeic acid we need. It's extremely expensive as a raw chemical, if you can find it at all.

More about the agents and a trouble shooting guide you find on my Caffenol blog
caffenol.blogspot.com

Best - Reinhold

@ all: if you have an urgent question, send me pm. This group is not very busy and also the 2 legendary flickr caffenol groups are not very busy anymore. The basics of coffee based development are known in the meantime and are no secrets anymore. So the pioneer days with huge enthusiasm of the protagonists are gone and made place for routine.

11 years ago.

Jim Kerslake ^club

Thank you Reinhold, that makes perfect sense.

I will buy a lot more soda - at least it's cheap :-)

Sadly, I only realised that pure caffeine powder was useless after I had already bought myself 200 grams of the evil stuff... so I have no idea what to do with it now, or how to get rid of it! I think it is quite poisonous because it is so strong - I'm surprised that it is so easy and cheap to buy.

Thanks again - your reply is very much appreciated.
Best wishes,
Jim

11 years ago.

imagesfrugales

Hi Jim, you are welcome and good luck for your next developments.

You can buy decaffeinated coffee and add the caffeine to at least 2000 cups, hahaha. Sorry that I'm rofl - I have no clue what you can do with caffeine.

Sorry again, I'm in a great mood because as I walked home I just salvaged a perfect working compact Yamaha hifi system with great speakers on the street waiting for the bulk garbage collection.

Best - Reinhold

11 years ago.

Jim Kerslake ^club

LOL - congratulations on your find, Reinhold.
Amazing what people will throw away...

11 years ago.

imagesfrugales

To be honest I don't know, Henrique. I always diluted first soda, then vit-c, then coffee and that was always my recommendation. But maybe I was wrong, the coffee dilutes much faster without vit-c and doesn't make foam. After all it probably doesn't make a difference. To be sure we need a side-by-side comparison.

10 years ago.

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