The Caffenol Process is a baffling alternative process and it is surprising to think that coffee can develop film and paper negatives! It does work and today we'd love to give you the tools and basics needed to try this for yourself. For this experiment please read the following instructions.
30g of Washing Soda
45g Strong Coffee
18g Vitamin-C Powder (from 1000mg Chewable Tablets)
1lt Warm water
Patterson hand tank or Equivalent (including spools).
Changing bag or light tight room (darkroom).
Ilford Rapid Fixer or Equivalent.
The great thing about this process is that it can be done with simple household goods. Washing Soda can be made by simply baking conventional baking soda in an oven at 200c for 35-40 mins. This process removes the hydrogen component removing it's reactivity to water, in effect making the baking soda into a water thinner, so for this experiment it is an essential part of the process. Now once you have all of your ingredients it is time to combine them, this is done by mixing them with one litre of warm water, at around 20-25 degrees C, firstly mix the washing soda, then add the vitamin C (from crushed tablets) to the mix, note it will react as they do contain bicarbonate of soda so be prepared for a mini volcano, lastly add the coffee and stir well. Once your mixture is complete you'll be able to develop rolls of film and even paper negatives (ie Ilford Multigrade etc).
Ilford Paper Development
For the development of Ilford papers we noted a few changes in it's reactivity: the solution works for around 8 to 10 prints with Ilford multigrade at 10x8, we have noticed a change in ISO sensitivity for Ilford papers, from the typical ISO 3 increasing to ISO 16, our experience with development times averaged around 2-3 minutes, noting that the longer it is in solution the browner the whites will be on the negative, resulting in an interesting blue toned positive, we have found that the developer works quicker at higher temperatures of around 20 degrees C or above. Examples Below.
Black and White Film Development
For developing black and white films, the ingredients can be halved to create a 500ml solution for standard hand tanks of 1 to 2 spools. Our recommendation would be to develop your roll/s of film for double the manufactures recommended timings (these can be found on their website/s) for our experiment we developed a roll of 120 Ilford FP4 for 13 minutes.
When developing the film it is essential to load the film in complete darkness, this avoids destroying your negatives as the film is highly reactive to light, once you have loaded your film into the hand tank you can develop. Start by adding the Caffenol solution you have made and develop for the required amount of time. Once you finish the development cycle, you can use tap water as a stop bath or Ilfostop equivalents to neutralise the developer, we usually run a stop bath for 1-2 minutes with tap water or 1 minute with Ilfostop. Next we'll be using a fixer, this is essential as it stabilises the film stopping any potential of further development or deterioration over time, we recommend using a fixer for 5 minutes. Lastly it is recommended to rinse your film in the hand tank for 5 minutes before hanging to dry, this remove excess fixer and helps to clean the film. Examples below from an expired roll of Ilford FP4.
Note for all processes after development we have used Ilford's own Rapid Fixer and Ilfostop (stop bath) products for both film and paper.
Disclaimer: it is extremely unwise to drink or ingest the byproducts of this developer!