Caffenol C is a very easy to use alternative technique to develop your films at home. According to my research online, this technique can be used for developing both black and white films and colored films but I have only seen the examples of black and white films. There are many different formulas for this technique but I will give you the recipe I found most useful by trying to find the right combination myself.
Due to it’s high acidity we prefer instant-coffee. If we want to see it from a chemical point of view, we can say that it has caffeine acid which is a reductor.
2. Vitamin C (Ascorbic acid)
To have a homogeneous distribution in the water we need Vitamin C powder.
3. Washing soda
You should use powdered washing soda. If you use crystallized version, the film will not develop. Washing soda is a rarefied version of sodium carbonate which is a base salt. You can use any other base agent for the process of developing but sodium carbonate is mostly used due to it’s availability.
In the videos I watched, I saw AdoLux Adofix fixer being used (for black and white film).
5. Distilled water
Used for avoiding lime stains on the film.
- Developing tank
- Waste cup
- Measuring cup (with 480 mL water [20°C] in it)
- 3 cups
- 1 spoon
- You must use latex gloves since you will be working with chemicals while you are developing the film
- First you cut the film from the tape and you roll it to the spiral of the tank.
- Wash the film for 1 minute by pouring water into the tank. At this point you shouldn’t shake the tank. You should slowly turn it up/down to mix. After washing the film the water is emptied into the waste cup.
- 480 mL water in the measuring cup is emptied into 3 cups equally.
- Put 40 grams of coffee into one of the cups (around 9.5 spoons), put 54 grams of washing soda into one of the other cups (around 4.5 spoons) and put 16 grams of vitamin C (around half a spoon) into the last cup. It will take time for the coffee to dissolve since the water is not heated After everything in the cups are dissolved, add vitamin C solution into the washing sodium carbonate solution. Afterwards add this combination into the coffee and mix well.
- Pour the solution into the developing tank. Turn it up/down for a minute without shaking it. After this turn the tank upside down every 3 minutes for a whole of 17 minutes. Empty the tank into the waste cup.
- Add water to the tank, mix, empty it. Continue this until there is no coffee left in the tank.
- Pour 480 mL fixer into the tank, mix for 5 minutes and empty into the waste cup.
- At last wash the film thoroughly with distilled water. Now the film is ready for scanning.