Caffenol is a film developer made from instant coffee, washing soda, and vitamin C. It sounds like a chemistry experiment gone wrong, but it actually works — and works well. Beyond the novelty, caffenol teaches you how developers actually function and proves that film processing doesn't require exotic chemicals.
Active time: 30-40 minutes Total time: 2-3 hours (including drying)
Familiarity with standard film development is recommended:
- Work in a well-ventilated area—even household chemicals benefit from good airflow
- Avoid inhaling washing soda dust when measuring
- Wear gloves when handling the mixed solution
- Never eat or drink in your workspace
- Standard fixer is still required and should be disposed of properly
What is Caffenol?
Caffenol uses three household ingredients that happen to fulfil the requirements of a photographic developer:
- Instant coffee — Contains caffeic acid, which acts as a developing agent
- Washing soda (sodium carbonate) — Provides the alkaline environment developers need
- Vitamin C (ascorbic acid) — Supercharges the development and improves results
The name comes from combining "caffeine" and "phenol" (the chemical family of traditional developing agents like hydroquinone).
Why Use Caffenol?
Educational Value
Caffenol demystifies development. Understanding that coffee develops film helps you grasp what's actually happening in any developer:
- Developing agents reduce exposed silver halides to metallic silver
- Alkali activates the developing agents
- The process is chemistry, not magic
Accessibility
You can make caffenol from supermarket ingredients:
- No photo shop required
- Useful in remote locations
- Much cheaper than commercial developers
- No hazardous chemical disposal concerns
Environmental Considerations
Caffenol is arguably more environmentally friendly:
- Biodegradable ingredients
- No heavy metals or harsh chemicals
- Can be safely disposed of down the drain (check local regulations)
Distinctive Results
Caffenol produces its own aesthetic:
- Moderate grain, good tonal range
- Slightly warm image tone
- Works well with many films
Caffenol was popularised by the online photography community in the early 2000s. Countless photographers have refined recipes and shared results, making it a well-documented alternative process.
The Chemistry Behind It
Understanding why caffenol works:
Caffeic Acid (from coffee)
Coffee contains caffeic acid and other polyphenols that can reduce silver halides. It's weaker than traditional developing agents but effective with enough time and alkalinity.
Sodium Carbonate (washing soda)
Developers need an alkaline environment (high pH) to work. Washing soda provides this, typically creating a pH around 10-11. The more washing soda, the more active (and contrasty) the development.
Ascorbic Acid (vitamin C)
Vitamin C is itself a developing agent (used in some commercial developers). In caffenol, it:
- Speeds up development significantly
- Improves shadow detail
- Reduces overall development time from 30+ minutes to under 15
Caffenol Recipes
Several standard recipes have emerged. All measurements per 500ml of water:
Caffenol-C (Standard Recipe)
The most common starting point:
| Ingredient | Amount | Notes |
|---|---|---|
| Instant coffee | 20g | Cheap instant, not freeze-dried |
| Washing soda | 27g | Sodium carbonate (NOT baking soda) |
| Vitamin C | 8g | Ascorbic acid powder |
| Water | 500ml | Room temperature |
Development time: 12-15 minutes at 20°C
Caffenol-C-M (Medium contrast)
Slightly modified for better tonal range:
| Ingredient | Amount | Notes |
|---|---|---|
| Instant coffee | 20g | |
| Washing soda | 27g | |
| Vitamin C | 4g | Half the standard amount |
| Water | 500ml |
Development time: 15-18 minutes at 20°C
Caffenol-C-H (High contrast)
For punchy, contrasty negatives:
| Ingredient | Amount | Notes |
|---|---|---|
| Instant coffee | 20g | |
| Washing soda | 35g | More alkali = more contrast |
| Vitamin C | 8g | |
| Water | 500ml |
Development time: 10-12 minutes at 20°C
Use washing soda (sodium carbonate), NOT baking soda (sodium bicarbonate). They are different chemicals. Baking soda won't provide enough alkalinity.
Mixing Caffenol
Ingredients to Source
Instant coffee:
- Cheapest supermarket brand works fine
- Avoid flavoured varieties
- Granules or powder both work
- NOT filter coffee, espresso, or beans
Washing soda:
- Found in laundry aisle
- "Soda crystals" in the UK
- Can be made by baking baking soda at 200°C for 1 hour
- NOT baking soda, borax, or caustic soda
Vitamin C:
- Pure ascorbic acid powder from health food shops
- Tablets crushed finely can work but may contain binders
- Sodium ascorbate also works
Mixing Procedure
Measure 500ml of water at room temperature (20°C).
Add washing soda first. Stir until completely dissolved. This takes a minute or two.
Add instant coffee. Stir thoroughly until dissolved. The mixture will look like strong coffee.
Add vitamin C last. Stir until dissolved. The mixture may foam slightly.
Let the mixture settle for 2-3 minutes before using. Some foam is normal.
Mix caffenol immediately before use. It oxidises quickly and loses potency. Don't try to store it for later.
The Development Process
Pre-soak (recommended): Fill tank with 20°C water for 2-3 minutes. This removes the anti-halation layer and helps even development. The water will turn blue/purple from the dye.
Pour in caffenol: Start your timer immediately.
Agitate: Continuous agitation for the first minute, then 3-4 inversions every minute thereafter.
Development time: 12-15 minutes for Caffenol-C at 20°C. Adjust based on your recipe and desired contrast.
Stop bath: Water is fine. Rinse 3-4 times.
Fix: Use standard fixer (Ilford Rapid Fix, etc.). Caffenol doesn't fix — you need commercial fixer.
Wash and dry: Standard procedure.
Film Recommendations
Caffenol works with most black and white films, but some perform better than others:
Excellent Results
- Fomapan 400 — Budget film, handles caffenol well
- Ilford HP5+ — Classic combination, forgiving
- Kodak Tri-X — Good results, slightly more grain than standard developers
Good Results
- Ilford FP4+ — Works well, may need slightly longer times
- Ilford Delta 100/400 — Modern emulsions work but designed for standard developers
- Kentmere 400 — Budget-friendly option
Variable Results
- Kodak T-Max films — Designed for specific developers, results may be inconsistent
- Ilford Pan F — Can work but slower films need longer times
Start with HP5+ or Fomapan 400 for your first caffenol experiments. They're forgiving and well-documented with this developer.
Troubleshooting
Negatives Too Thin (Underdeveloped)
- Extend development time
- Ensure water is at 20°C (colder water slows development)
- Check that washing soda fully dissolved
- Use more vitamin C for extra developing power
Negatives Too Dense (Overdeveloped)
- Reduce development time
- Reduce agitation
- Use Caffenol-C-M recipe with less vitamin C
Uneven Development / Streaks
- Pre-soak to remove anti-halation layer
- Improve agitation consistency
- Ensure coffee fully dissolved before use
Brown Staining
- Extend final wash time
- Some staining is normal and doesn't affect image quality
- Usually fades with thorough washing
Excessive Grain
- Expected with caffenol — it's a moderately grainy developer
- Use finer-grain films (FP4+, Delta 100) if grain is a concern
- Slight overexposure can help
Stand Development with Caffenol
Caffenol works well with stand development:
Mix caffenol as normal but use half the vitamin C (or omit entirely for maximum stand time).
Pour into tank and agitate for first 30 seconds only.
Leave completely still for 60-90 minutes.
Optional: one gentle agitation at the halfway point.
Stop, fix, and wash as normal.
Stand development with caffenol produces very even results and enhanced compensating effect, useful for high-contrast scenes.
Beyond the Novelty
Caffenol isn't just a party trick. Photographers use it seriously because:
- It works reliably — Thousands of documented successful developments
- Results are good — Not just "acceptable" but genuinely usable negatives
- It teaches fundamentals — Understanding caffenol means understanding all developers
- It's sustainable — No special chemicals to buy or dispose of
Once you've developed a roll with coffee, you'll never look at a bottle of D-76 the same way. You'll understand that developers are just chemicals that reduce silver — and those chemicals can come from surprising places.
Keep notes on your caffenol experiments. Small variations in coffee brand, water hardness, or temperature can affect results. Recording what works helps you refine your personal process.
Additional Resources
The caffenol community has documented extensive variations and experiments:
- Wine developers — Tannic acid from red wine
- Herb developers — Various plant-based developing agents
- Beer developers — Yes, it's been tried
Caffenol is a gateway to understanding that film development is fundamentally about chemistry, and that chemistry is more flexible than commercial products might suggest.