For what it’s worth, this is my own personal recipe, I’m still experimenting with it, but I’ve been pretty happy with the results. If I change anything, I’ll come back to this post.
For starters: I am using a Paterson universal tank. I keep the 1liter water measure, because that will fill up that tank to the brim. I fill to the brim because I’m using at least a semi-stand development method, and I want as little air inside the tank as possible. My recipe is based on Reinhold’s, but converted to the American volumetric measuring system, and from doing some digging online and off, I’ve included a few other useful rules of thumb, like developing times.
Astro Beck (who is a friend of my Alt.Process instructor) told me that caffenol tends to “contaminate” plastic to some degree and exhausts fixer, et. al, faster than normal processes, so it’s best to have a tank and all other chemicals set aside exclusively for caffenol use. If all you do is caffenol, I’m sure it wouldn’t matter, but this could be important if you’re still developing with other chemicals, or share equipment with someone who does.
I’m using the C-L recipe because I have found Potassium Bromide to be essential. I know there are recipe/film combinations that work without it, but I shoot mostly Kodak film, and Kodak films tend to fog badly without KBr.
I’ve listed ingredients in the order that they should be added, usually mix hard and wait for the water to clear to see if more mixing is needed. The KBr that I have is a combination of powder and large crystals. The hard crystals are fine in the solution, but they need a bit of soaking before they’re ready to be crushed down, and then more soaking before they completely dissolve. Coffee is last because you won’t be able to see anything after it’s added. Generally, I use water at around 70F (70 degrees Fahrenheit) though the original recipe calls for 68, as it takes enough time to mix that the water cools down (unless it’s Summer, then maybe it should be 66F…will experiment and check back).
Water (1000ml) – for two rolls, a full tank
Washing soda (3 1/2 tsp)
Vitamin C (2 tsp)
Potassium Bromide (~1/4 tsp) (KBr)
Instant coffee (8 tsp)
Water (500ml) – for one roll (I know, you only need 300ml, you could do a third of the 1liter recipe)
Washing soda (>2 tsp)
Vitamin C (<1 tsp) (a heaping teaspoon)
Potassium Bromide (~1/8 tsp) (KBr)
Instant coffee (4 tsp)
After all ingredients are mixed, let sit for 5 minutes (this is a good time to start presoaking your film as well). After 5mins/when you’re ready, dump the water out of the tank and pour in the developer. Here’s a good rule of thumb for developing times:
ASA100 – 15mins
ASA200 – 30mins
ASA400 – 45mins
etc. Every extra stop, add 15mins.
I use semi-stand development, which is something like 10sec immediately, then 5sec after that at 1min, 2min, 4min, 8min, 15min, 30min, etc.
This seems to work with all regular Kodak black & white films (I haven’t tried Double-X, etc), so it’s more a case of what speed you’re shooting at rather than what film you’re using. Since you’re agitating much less, grain is reduced, and I particularly like what it does to Tri-X.
I’ll admit that my negatives look pretty thin using this formula, however, they are extremely low contrast, so no detail is lost.
I’ve found that adding more coffee will make the film develop faster, but mostly has the effect of making the highlights block up, so definitely go light on the coffee if you’re pushing film a few stops.
For more information on where I sourced my materials and how much I paid, click here.
(note: I forgot to transcribe my recipe before I moved, had to go back and get my notebook, so my last roll of film was just slightly off, as I went by new/different calculations)