Visit my new blog

I´ve decided to split my blog in two. I will continue to post DIY projects and musings here, but (serious) pictures, taken on film of course, will be posted in my new blog "Silver Halides"

I now consider Caffenol to be a developer like any else. As such the new blog will focus more on the pictures, rather than the process.

Tuesday, 23 November 2010

Does Caffenol expire, or can it be stored?

Its been said that the Caffenol ingredients can´t be diluted in water prior to use, as they will rather quickly loose their effectiveness. As with most things, at least according to my experience, this depends. If you are happy with your solutions still working 6 weeks after dilution, then yes, solutions can be premixed. By this I mean mixing with water as to be ready for mixing when developing, negating the need to measure up and dissolve powders when the time comes to develop a film. It also helps reduce measuring inaccuracies, as you will be operating with much larger amounts of the different components.

There are three main ingredients to Caffenol-C-H and C-M. Sodium Carbonate, Coffee and ascorbic acid. C-C-H may need a dash of Potassium Bromide, I´ll come to that later.

My Paterson 4 tank takes 500ml of developer for a 120 film. I therefore want to measure up three equal parts, volume, to make up the developer. This means that each premix solution needs to be 3x more concentrated before mixing. I take three two-litre compressible stand bottles such:

Sodium Carbonate: 3x54 grams pr litre (162g/l), two litres = 324g/2l
Ascorbic acid 3x16 grams pr litre (48g/l), two litres = 96g/2l
Coffee (instant) 3x40 grams pr litre (120g/l), two litres = 240g/2l

This will result in 6 litres of developer, enough for 12 shots of 500ml (1/2l) in a Paterson 4 tank

If you need Potassium Bromide, premix it to a concentration of 1g/10ml and add between 2.5 and 10ml (0.5g - 2g/l) to the mix if needed. Faster films typically need more, slower films may even do without.

I´ve done this. Apart from the advantages listed above, you will be able to start development much quicker as all you need to do is mix the solutions together and use more or less immediately. You need not wait for the powders to dissolve and the solutions to settle. I mix the carbonate and ascorbic acid first, then add the coffee last.

Does it work? Well all the films from the previous blog entries here have been developed from the same premixed solutions. A few examples from last film I developed can be seen below. At the time of developing the solutions had been stored for over 6 weeks!

Kowa Super 66, Kowa 85f2.8, TMAX100, EI 80, Caffenol-C-H, 16min@20C


Kowa Super 66, Kowa 85f2.8, TMAX100, EI 80, Caffenol-C-H, 16min@20C


Kowa Super 66, Kowa 85f2.8, TMAX100, EI 80, Caffenol-C-H, 16min@20C


Kowa Super 66, Kowa 85f2.8, TMAX100, EI 80, Caffenol-C-H, 16min@20C
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4 comments:

  1. Ezzie1 December 2010 at 10:04

    A small update. The coffee has expired, it took a good 7 weeks, during which time we´ve experienced the coldest autumn in ages, so it was stored cold. No matter, replenishing the coffee is the least of my problems.

    Results from two more films will be posted shortly. Still using the same premixed chemicals, but with a new shot of coffee.

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  2. k24 August 2011 at 23:32

    Eirik, thanks for your blog. Great photos and your notes are very clear and easy to follow.

    I've just started combining my pre-diluted solutions. On Reinhold's blog he writes that bubbles appear when the VitC is added to the soda. Do you find that when adding the solutions together that you get bubbles. I didn't see any...

    Also, do you think these solutions could be stored in plastic juice bottles or do they require glass?

    Cheers
    Kev.

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  3. Ezzie5 February 2012 at 13:07

    Sorry for the late reply. For some reason I haven´t been able to see the comments for some time.

    With regards to bubbles. No, I don´t get any when mixing soda and vitamin-c. But I do get froth from the coffee. I tend to pour it into the mix last, and slowly - leaving the froth behind.

    I store my solutions in plastic compressible bottles, to minimise air in the bottles when the level of the solution sinks.

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  4. Martin21 May 2013 at 13:19

    Hello,
    today i was developing my 13x18 film sheets in drums. I have just two drums and yesterday i was shooting 10 plates, this means 20 film sheets. I was developing the hole day! Do you have any expirances with tank developing with caffenol? Any DIY tips?
    Thank you very much!
    Cheers
    Martin

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