Caffenol is a ‘brew’ or ‘soup’ that can be made for developing film and or paper in. The ingredients are vitamine C powder, washing soda and instant coffee, hence the name Caffenol. I’ve been using Caffenol for some years now and have gotten some great results, to my liking anyways!
The recipe I started from is the Delta STD which I found on Caffenol.org I tweaked it slightly and so this is what I do.
-Pre soak the film (while in the developing tank) in room temperature tap water while doing the following.
-Boil some water to about 35-40˙C
-Pour the water into two different measuring cups. 150ml and 200ml
-In the 150 ml water I add 6 heaping tablespoons of coffee (cheapest instant caffeinated) and 1 of vit-C powder. Stir well because there is always some residue. Sometimes I leave it to sit and settle because it bubbles up a little bit.
-In the 200 ml water I add 10 tablespoons of washing soda. But….
a) The original DeltaSTD recipe says 6 tablespoons but I do ten of the washing soda because it is not the powder but bicarbonate (i.e. crystals) and I read somewhere that it is 2.7 times the washing powder. So I use 10 tablespoons of the washing soda.
b) while mixing washing soda in the 35-40˙C water it brings the temp down right away to about 20˙C. So when I mix the 150ml (coffee+vit.C) and 200ml (washing soda) together the final temperature is usually around 25 degrees.
-For developing. First minute agitations, and then the rest of the 9 minutes with a few stirs/agitations every minute.
-After 9 minutes, all the caffenol goes down the drain. I rinse film in cold water until the water doesn’t have a trace of the coffee colour. I suppose you could use a stop bath but I don’t.
-Then fix for at least 6 minutes (I use the Ilford stuff)
My best and or favourite results so far have been using Kentmere 400. But I do use old expired colour films as well.