It must’ve been a couple of years ago when I first read about developing black and white film using instant coffee but it wasn’t until late last year did I first give it a go. My first test was a complete disaster – I had shot a roll of Kentmere 400 in a Voigtlander Vito B and it came out completely blank. Upon inspection of the camera, it turned out that the shutter was sticky and so never opened even though you could hear the shutter click.
Never one to give up, I tried again but this time I ran a roll through my Canon AV-1 which I’d used recently so I knew that it worked properly and success!! I couldn’t quite believe it when I opened up the developing tank and found a strip of developed negatives. I guess instant coffee has its uses, just not for drinking.
In both of my tests, I opted for the Delta-STD recipe on the Caffenol site. Although the recipe called for washing soda (sodium carbonate), I could only find soda crystals (sodium decahydrate) here in the UK and so had to multiply the amount of soda crystals by 2.7 in order to account for the extra water.
Given that my largest developing tank was around 500ml and using the Delta-STD recipe as a starting point, my mix was as follows:
- 500ml water
- 32.4g soda crystals
- 10g ascorbic acid powder (a.k.a vitamin C, easily sourced off Amazon/eBay)
- 22g instant coffee (I just used the cheapest one from Tescos)
The method was pretty straightforward. Weigh everything out, dissolve the soda crystals and ascorbic acid in half of the water. Next, dissolve the instant coffee in the rest of the water and add this to the soda/ascorbic acid solution. Mix thoroughly and leave to stand for a bit until the temperature equilibrates and then you’re good to go (assuming that you’re already familiar with black and white film developing and have all the relevant potions).
My initial tests were with Kentmere 400 but I used the same timings as quoted for developing Ilford HP5+ (10 minutes at 20C). If the caffenol developer is a bit warmer/cooler than 20C, you can always compensate by adjusting development times. I usually have this table stuck up in my ‘darkroom’ for reference or you could use this.
You can use the developer as you would normally. My workflow is usually five inversions at the beginning and then again for every minute until time’s up. If I have a couple of rolls to develop on the same day, I’ll reuse it but I’ve never put more than four rolls of 35mm film through 500ml of caffenol so can’t comment on its life expectancy.
Most folks rinse the film and then either use an acid stopbath or go straight to fixer. Seeing as I have stopbath on hand, I’ve always used it. I stop for two minutes, fix for six, rinse, pop open the tank, add a few drops of wetting agent (in my case, Mirasol) and let the film sit in that for a bit while I tidy up the work area. After that, it’s ready to be hung, dried and scanned.
Here are some results from various caffenol and film combinations. All shot at box speed (ISO 400).
Kentmere 400 developed in caffenol, shot using a Minolta X-300
Ilford HP5+ developed in caffenol, shot using a Minolta X-300
Kodak Tri-X 400 developed in caffenol, shot with the Canon AV-1