The original Caffenol Recipe and Black Caffenol

Caffenol was first introduced by Dr. Scott Williams and the Technical Photographic Chemistry 1995 Class of Imaging and Photographic Technology Department, School of Photographic Arts and Sciences of the Rochester Institute of Technology.

The paper produced about Caffenol can be read here and the original recipe was this one:

Coffee Two (2) Rounded Teaspoons
Baking Soda Two (2) Rounded Teaspoons
Potassium Hydroxide Added to pH 9.0 (approximately One (1) Rounded Teaspoon)
Water 12 oz. or 352 milliliters
Temperature 85 F
Time 25 minutes

Baking soda and Potassium Hydroxide should form a buffer solution to rise the pH of coffee which is acidic and does'nt allow developper to 'penetrate' the film emulsion. The team of Dr. William used also a temperature above 20ºC, 85ºF that is aproximately 30ºC.

The recipe, for simplicity of usage was modified by others, giving the well known recipe that is reproduced at Digital Truth:

Water 8fl oz

Arm & Hammer Washing Soda 2tsp

Folger's Coffee Crystals (not decaf) 4tsp

This last recipe is to be used at 20ºC and takes in average 30 minutes to develop a film.

The problem with this last recipe is that most of the people using it don't control the pH and temperature, the original recipe is more clear and says temperature and pH. And Dr. William was careful not fixing the amount of Potassium Hydroxide but the pH to be reached.

Having this in account, I also proposed to Digital Truth my alternative Black Caffenol to be listed in their collection of recipes, what they accepted after having tested it. Important is to use a pH of 10,4 at 20 ºC, what needs about 5 g of Sodium Carbonate or a little more. The pH is higher than in the original recipe of Dr. William but the temperature is also lower and the time is longer. I think that if temperature is used, the pH and time should decrease too.

The Caffenol Cookbook Bible

Today I decided, finally, to read the Caffenol Cookbook Bible, a 40 pages pdf book with the main caffenol recipes used today. I could have read it before, but I wanted to develope my own caffenols and then, at the end, compare my findings with those of other people.

First of all, I liked very much the way the book is presented and all the contents. Congratulations to the authors. I didn't read all contents until now but I will, specially the chapter about scanning because I am totally ignorant in this matter.

The Caffenol Cookbook includes contributions of 9 persons. dispersed in the world and it was only possible in the Era of Internet.

After a short acknowledgments, a page with a beautiful phrase of Reinhold G., which translates what we, the infected by Caffenol, feel about it. First we think it must be a joke but after the first successful developments, we all get the fever.

The Book continues with some forwords of Mike Overs, from there I liked very much when he says «The word "other" is not a cloak of false modesty, but a mark of admiration for my fellow contributers».

Reinhold G. tells us then about the few ingredients used in the different caffenols and then the Book enters the recipes chapter with 2 main parts, Caffenol Metric, Caffenol Volumetric.

Starting the chapter Caffenol Metric, we find as first the recipes of Reinhold G., respectively, Caffenol-C-M, Caffenol-C-H and Caffenol-C-L. The names were chosen as follows: caffenol because the developer has as main developing agent coffee, C for Vit. C and M, H, L reflect the properties: M for low and Medium speed up to 100 ASA, H for speed enHancing (I think) and L for Low pH.

Reinhold recipes became classic and I am sure they do well the job. The main ingredients are Sodium Carbonate anhydrous, Vitamine C and Instant Coffee, mixed by the order given. 2 of them use Potassium Bromide as antifoggant and accutance enhancer. All 3 recipes use 40g / liter of coffee. Caffenol-C-H ist identical to C-M with 16g/l Vit. C and 54g/l Soda, but needs 1g of Potassium Bromide that makes a great difference in quality. Both C-M and C-H take 15 minutes as starting point. The most different of these 3 developers is the Caffenol-C-L with less Soda, just 16g/l of soda and 10g/l of Vit. C.

After the recipes of Reinhold, the Book includes a suggested variation to the recipes of Reinhold by Eirik Russell Roberts with 75% of the soda contents proposed by Reinhold. So, the author kept Reinhold's nomenclature, adding a (rs) to them, where rs means reduced soda version.

In the part of Metric Caffenol, we find the Caffenols from Dirk Essl. He proposes 3 Caffenols, Caffenol Delta-STD With 45 g/l coffee (similar to Reinhold's coffee amount), 20 g/l of Vit. C (more than Reinhold's recipes) and only 24g/l of soda, less than 50% of Reinhold's. Interesting is that the developing times are shorter, 9-10 minutes. Another difference is that Dirk follows another mixing order: coffee, soda and Vit. C but he suggests to dissolve coffee and soda separately to make dispersion easier. The second recipe of Dirk Essl, Delta Micro) needs only 22 g/l of coffee, 10 g/l of Vit. C and 32g/l of soda. Should be used only for high contrast Microfilms. The last recipe of Dirk is called Caffeafine and is a 2-step developer and should be listed in volumetric Caffenols because he uses tsp as unit. I think, by the name, this 2-step developer will give fine grain.

In the part of Caffenol Volumetric we may find the contributions of the pair Martina Woll & John Caradies. They propose 2 recipes:

9,5 slightly heaped tsp of coffee
4,5 slightly heaped tsp of soda
0,5 tsp of Vit. C powder

This developer takes about 15 minutes, they already calculated for different brands, 17 minutes for APX 100, 14 minutes for Kodak Tri-X 400 and so on.

Martina & John follow here the same mixing order of Reinhold's recipes but in the next recipe that they call Caffenol CM-RS they change the order:

4 tsp arm and hammer washing soda
1&1/2 tsp of Vit. C powder
1/2 tsp iodized salt
5 rounded tsp chep instant coffee

This last recipe shall develope in just 11 minutes.

The other developer included in the part of Caffenol Volumetric is Sumatranol 130 from John Nanian, which is also a developer for prints, but I didn't catch yet all the procedure of the preparation but one think is remarkable, he doesn't use soluble coffee but real coffee prepared by himself. He mixed then the Caffenol C with Ansco 130 developer.

Now, after reading all the recipes in the excellent Caffenol Cookbook Bible, I am more rich in information. But also it was rewarding to me to see that my own recipes are not cloned from any other. And I didn't find instructions about reusing Caffenols, what I would like to achieve too.

Blend Caffenol tests

As explained in the previous post, Blend Caffenol results from a marriage between Caffenol Black and the Orange developer. Making mentally the calculation of soda amount, I miscalculated 23 instead of 28g and I used just 20 g/l, thinking that it should be enough. I measured a pH of the same value, i.e., 10,4 like the other two developers.

But, because Coffee and Vit. C are superadditive, the developing time decreases to 15 minutes, instead of the 60 minutes that each developer alone needs.

I prepared, on last 10th May, 2 Liter of this hybridus developer, Blend Caffenol, and divide it for 4 amber bottles of 500ml each. Let us remember the recipe of Blend Caffenol:

1000 ml water

10 g soluble cheap coffee

20g Sodium Carbonate

5 g of Vitamine C

 In order to prevent its deterioration and permit the reusability, I added a pintch of Potassium Metabisulfite, lets us say 0,5 g/l.

With one of the 500ml bottles I already developed 4 rolls, the last two yesterday. One of the rolls, Agfa APX 100 ISO needed 40 minutes according to the proof of the tail I undertook first. The roll was well developed, slightly foggy, nothing serious.

Pentax P5, Agfa APX and Blend Caffenol

Pentax P5, Agfa APX and Blend Caffenol

Pentax P5, Agfa APX and Blend Caffenol

Pentax P5, Agfa APX and Blend Caffenol

Pentax P5, Agfa APX and Blend Caffenol

Blend Caffenol

Important update at the end!

Starting by preparing Caffenol black and the Orange developer as listed below,

I repared that both have the same pH value and if I mix them, then the result would have the same pH value and by mixing them in a fifty-fifty proportion the final solution will have half the amounts of chemicals per liter and the recipe would be then:

1000 ml water
10 g soluble cheap coffee
28 g Sodium Carbonate*
5 g of Vitamine C

What changes then? The developing time, because coffe and Vit. C are superadditive. In fact the developing time drops to 12 or 15 minutes. The first roll I developed it in just 10 minutes but the film is slightly underdeveloped. Next time I will try 15 minutes. To the 1 liter developer I added then a pintch of Potassium Metabissulfite to see if it helps to preserve the solution for reuse. I will test this today.

Another suggestion is to work with a lower pH reducing the amount of Sodium Carbonate. Developing time will increase but the grain will be finer.

Blend Caffenol, Shangai GP3, 10 minutes semi-stand development

* Note: I calculated wrong (23 g). This was a lucky mistake, because in reality we only need 20 g/Liter of Sodium Carbonate. Please update the recipe as follows:

1000 ml water
10 g soluble cheap coffee
20 g Sodium Carbonate anhydrous
5 g Vitamine C

Mixing order as given in the recipe. The pH value should stay in about 10,4-10.6. Developing time is 15 minutes for the first roll. You may reuse at least within 24h, more time is not known yet.

Caffenol Black (or Solo) - new preparation instructions

If you already succeeded using Caffenol Black and you find it difficult to prepare, I have a suggestion that I use myself too:

Dissolve 50g Sodium Carbonate anhydrous (or equivalent) in 5 liters water and store in a jerrycan. This is a 1% solution, if you use other units, calculate 1% of the weight of the water quantity.

Now, when preparing for instance 500 ml of working solution, dissolve 10 g soluble cheap coffee, not arabic, not decoffeinated, in 200 ml water. After the coffee is completely dissolved, start adding the 1% solution of Soda until you reach 10,4-10,6 pH. Complete with water to make 500 ml if needed.

I think this is very practical and allows you to adapt the soda amount according to the acidity of the coffee used. For instance, if you use 200ml coffee solution and 300ml soda solution, you have 3g/500ml what is 6g/liter instead of just 5g. As a matter of fact, the real amount of soda is between 5 and 6 g, when using 20g/liter of coffee.

Polypan F + Caffenol Black (and Photoscape)

Caffenol Solo (or Black) - Update

It is rather difficult to express our ideas in such a way that the others understand and may reproduce what we have done. So, and in order to avoid the killing of a (for me) great developer, I will try to pass all relevant information here in the blog. The recipe must be updated as follows:

500 ml water
20g soluble cheap, not arabic, not decoffeinated
Sodium Carbonate anhydrous q.b. to reach pH of 10,4 to 10,6 (it is 5 g or more per liter)
Water to make 1 liter

Instructions:

First dissolve the coffee in 500ml water and then the alkali, in this case Sodium Carbonate. Stir until all grittiness is dissolved, addd water to make 1 liter and use immediatly. Make 60 minutes semi-stand development at 20ºC. Of course you may reduce the quantities to the half if you don't need 1 liter of developer.

Gratefulness

I express here my deep gratitude to Reinhold of the superb blog Caffenol, for having tried the original recipe where I wrote 5 g of Washing Soda as a fixed value. He only got 9,9 of pH value and the Stripe of Polypan F was underdeveloped and gave no details in shadow.

Here an example of what you may reach with Caffenol Solo and Polypan F:

Is Caffenol a good option as film developer or is it just a curiosity?

Most people begin using Caffenol just to see if it works. And the most spread recipe for Caffenol is the one reproduced in the site of Digital Truth from which I made Copy & Paste here.

Caffenol

Caffenol film developer

Water	8	fl oz
Arm & Hammer Washing Soda	2	tsp
Folger's Coffee Crystals (not decaf)	4	tsp

Mixing Instructions: Mix soda until completely dissolved and solution is clear. Add coffee, mix until all grittiness is gone and solution is uniform. Let stand 5-10 minutes until microbubbles clear. Use within 30 minutes.

Dilution: Use undiluted.

Usage: 30 mins.

Notes: Gives imagewise stain and general (fog) stain. All teaspoon measures should be level, or slightly rounded for coffee crystals.

Everybody that tried this recipe comes to the conclusion that OK, it works, the film is developed in 30 minutes but it is a dirty developer, the film remains foggy and stained and with hudge grain. For playing with it is OK but to have decent developed films, better another choice. There have been several contributes to turn Caffenol a decent developer, mainly from Reinhold who proposed several recipes of Caffenol combined with Vitamine C or, better said, with sodium ascorbate.

Recently, at Flickr, somebody started complaining about caffenol and he (or she) was going to give up using Caffenol for the reasons I said before: stain, fog, grain.

I started then to test several possibilities, under my opinion that a developer must be as simple as possible and with the minimum amount of chemicals. Using stripes of film, I made a solution of coffee and start increasing the amount of alkali, at that time I used Sodium Hydroxide, until I was sure that some development would happen. I exposed then cheap films like Polypan F and Shangai GP3 and the results were more than satisfying. I can say now that coffee is an excellent developer, at least for the films used.

The recipe of Digital Truth given above is a bad recipe. On the other hand the quantities measured in spoons may work differently for different people.

The recipe I use now is like this and I am calling it Caffenol Black or Caffenol Solo:

500 ml of water
20 g of soluble coffee
5 g of Sodium Carbonate*
Water to make 1 liter

First dissolve the coffee in water and then add the alkali. The order is coffee-alkali and not like the recipe of Digital Truth says. It works much better. Sodium Carbonate can be added as solution, if you dissolve 100g in 1000 ml, use 50ml of this solution that may be kept for other Caffenol batches.

The Caffenol should be used just after preparation and it takes some 60 minutes (and not 30 minutes) to develop your film without stain, without fog and with very acceptable grain.

* Important notice: after discusssing this with Reinhold, who had bad results with the recipe above (underdevelopment, no shadow details), the 5g/l are not a must, Important is to achieve the right pH that is about 10,4 to 10,6, according to my cheap pH-meter. Different coffees have different acidic properties and may need more or less alkali. I even have used Sodium Hydroxid, adding it drop by drop until I reach pH 10,4 and it worked.