Someone in the caffenol Facebook group asked if there is a faster development process then caffenol, and I referred him to Diafine, a quite fast 2 step developer. (3+3 minutes for most films.) At the same time I thought that this should allbe possible with normal caffenol, as it is possible with all film developers: You increase temperature, you reduce time. Normally, higher temperature adds contrast, but if you develop for too short (temperature too high), you may get uneven development.
I started searching around if anyone has done development at 40 degrees C, but did not find anything. I had anyhow two films to develop, so why not try it myself. I mixed up some Caffenol-C-M and tried to get the temperature at about 40 degrees. After stirring I measured 38 degrees Celsius and poured the developer into the tank. After 6 minutes I measured again, the temperature did go down to 30 degrees Celsius and I removed the developer. I did not warm up the fixer, just used it at 20 degrees Celsius. I was a bit worried that the emulsion would crack, but hey, this is an experiment and careful inspection of the negatives shows no signs of cracks in the emulsion.
The upper row shows scans from a cheap ISO 200 color film exposed at EI 400. Contrast is a bit high, but nothing to worry about. Of course there is lots of grain, as this a C41 film.
The lower row shows some proper B&W film. Rollei Retro TONAL 100. An orthopanchromatic film on a synthetic film base. Interesting enough, grain shows up as well, which is not that prominent on scans developed in the Delta Recipe.
Conclusion: If you are in a hurry, you like contrast and you like grain even on low/medium speed films, just raise the temperature, and adjust the developing time accordingly.
If you have any suggestions on how to develop films in caffenol at higher temperatures or even have other crazy ideas, feel free to send me a message using the contact form.
If you happen to be on facebook, feel free to join the wonderful caffenol group, it’s growing every day with loads of nice people from all over the world.