film developer
Caffenol-C-M
Handle chemistry safely
Wear gloves and eye protection, work with good ventilation, and read the supplier’s safety data sheet before use. Hazard information here is a summary, not a replacement for it. Dispose of all photographic chemistry correctly, in line with local laws and your local authority’s guidance. Never mix waste solutions, and check the supplier’s safety data sheet before disposing of anything.
Ingredients
| Sodium carbonate (anhydrous (washing soda)) | 54 g |
| Ascorbic acid | 16 g |
| Instant coffee | 40 g |
| Water to make | 1 L (author starts with 1 L of water rather than making up to volume) |
Notes
Dissolve the soda, then the vitamin C, then the coffee, letting each dissolve fully. The soda warms the solution slightly, so let it cool back to 20 °C. The author gives 15 minutes at 20 °C for ISO 100 films, with 30 seconds of initial agitation then 3 inversions a minute. It is one-shot and does not keep.
Source
Caffenol-C-M, recipe, Reinhold (caffenol.blogspot.com) (2010)
Amounts as published. Chemical forms (anhydrous, monohydrate and so on) change the weights, so match the form listed.