Caffenol -- an experiment, and why I'll look elsewhere

I recently tried Caffenol ( 27 g sodium carbonate + 8 gr ascorbic acid + 20 gr Folgers in 500 CC water) to develop a roll of Tmax 100 and found that it worked pretty well, though base fog was high -- the sign, I read somewhere, that perhaps the mix is too alkaline. I did notice that one side of some of the photographs (120 film in a Hasselblad 500C) was a bit lighter than the other, as some have noted on the internet.

So I decided to try a less active version of 10g carbonate + 2g ascorbic + 10g coffee in 500ml water. I split the mixing into two portions of 250 ml each, adding first the carbonate and then the ascorbic acid to one beaker, and the coffee to the other 250ml of water. I wanted to be very sure that the coffee was fully dissolved. I added the coffee mixture to the other beaker and stirred it fully. I then added 5ml of a solution made by dissolving 10g of salt in 100 ml water, the idea being that this would reduce fog while also extending developing time.

I developed a roll of 120 TMAX 100 in this mixture for 28 minutes, agitation on the minute, and was generally disappointed -- now both edges of the length of the film was overdeveloped (leading to brighter stripes along the side of each image when scanned). I come away with the impression that Caffenol does not agitate in a small tank as readily as other developers. Perhaps the best method is to use a rod to lift spiral reels in and out to agitate and transfer from bath to bath. I also wonder if the oils seems floating on the surface of the developer could be a culprit -- could the oils attach to the surface of the film and remain in place to a greater extent in the middle portion of the roll of film than at the edges where agitation move the developer around more? I had the idea of getting one of those measuring cups used when making gravy that have a tubular spout that runs all the way to the bottom of the cup, so that fats will rise to the surface and will not be poured into the gravy because the spout draws from the sauce at the bottom.

Perhaps one technique would be constant agitation. But while I find that Caffenol can produce some nice images as scanned through the fog, there are other developers that do not have this edge development problem and produce images that are just as attractive. If others have found a solution for the edge development problem, I'm certainly interested in hearing it.

Have you tried printing one of the negatives? When I first tried coffee developers I was aghast at the miserable looking negatives - they scanned horribly and looked barely printable. They printed like a dream! The stained, foggy look was invisible to the paper.

Now I'm not saying your experience is different than you describe, but the actual print from one of these negatives will tell you far more than a negative scan.

I never take any special steps in using coffee developers, just the standard 1 min agitation and then 10 seconds every minute after that - one or two roll tank. 4 tsp coffee, 2 tsp washing soda, 8 oz. water, one tsp vitamin C powder. I am not at all careful about the measurement. Not everyone should copy my "relaxed" approach, but it works for me : >)

If you do the math, you've added very little salt. 5/100*10 = 1/2 gram of salt. Probably having little effect.

I would suggest maybe a little bit more solution for more even development. The caffenol, being coffee based, can froth easily, so potentially the upper strata could be less consistent due to froth and bubbles. You didn't mention what developing system you use, but I think my Paterson reel system requires 550ml to do a 120. I'm not positive because my darkroom is at home and I'm at work. You could mix up 600ml in such a situation. I think last time I mixed some up, I mixed a liter and did a 120+35mm at the same time.

I've been meaning to try this. Does anybody have a link that shows exactly the kind of washing soda one needs to do this? I'm not a chemist and can't distinguish one product description from another.

Even though I've never tried caffenol, I tend to agree with Whitey that a darkroom print will reveal a lot more than a negative scan. I've learned this the hard way living without a darkroom for a year now.

- Thomas

i don't measure any of the ingredients when i make caffenol, except for the water.
i am accustom to the negatives looking a little think and foggy and stained
and they print and scan very well. i also add a few 100cc's / L of print developer
( ansco 130 ) in with my poorly measured caffenol c .. i don't measure that either.
sometimes i do the agitation thing 10 seconds every min after the first min of continuous
like i would any film developer, i have also done it in a rotary drum, but i tend to stand develop
all my film and i have no complaints.
try to print them ( like whitey says ) the look of the film has nothing to do with how will it will print.

You might want to look up Mark Anthony's or is that Antony's( I think it's Anthony with the "h")) website. He is a subscriber here and has used coffee developer. I think that he said that there was a crucial period that had to pass after mixing to allow the bubbles to subside and before the mixture started to lose its strength

I have seen several prints in coffee and while the negs looked washed out, low contrst and thin the prints were good.

pentaxuser

I don't think uneven development will disappear in optical printing. The general fog and murk of Caffenol negatives seem not to be a problem either in optical printing or scanning, but when I've had similar problems to what the original poster describes, they really have seemed to represent different levels of development---more true density in one part of the negative than another.

It's a wonderful developer when things work right, but I wish I could get its behaviour a little more consistent. I've done quite a bit of experimenting to try to pin down the cause of overdeveloped edges, but no luck yet (the fog level seems to be somewhat random from roll to roll too, though that's more of an aesthetic preference than a serious practical problem).

-NT

One cannot hope for consistent results unless one weigh and measure precisely.

Also adding about 3 g potasssium bromide per litre is said to get rid of the fog, havent tried it yet ordered KBr yesterday.....

Interesting about the oils mentioned, those can be removed by filtering the brew (I also mix the cofee separately first in about half of the water) in an ordinary cofee filter...... doing that I would mix a little extra of the coffee, to make up for fluid lost in the filter...

hi erik

i have been using caffenol since 2005 (THANKS WHITEY!) and NEVER
had inconsistent results or oil in my solution
my coffee is just that bad .. and i just eyeball everything

folgers ?! maybe it is those "flavor crystals"

Thomas here is a link for you. http://www.acehardware.com/product/index.jsp?productId=3549579&CAWELAID=351933682 I know Cub foods carries it in your area.
http://householdproducts.nlm.nih.gov/cgi-bin/household/brands?tbl=brands&id=3005022

Thank you, Brian!

Brian Bullen said:

Thomas here is a link for you. http://www.acehardware.com/product/index.jsp?productId=3549579&CAWELAID=351933682 I know Cub foods carries it in your area.
http://householdproducts.nlm.nih.gov/cgi-bin/household/brands?tbl=brands&id=3005022

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Brian Bullen said:

Thomas here is a link for you. http://www.acehardware.com/product/index.jsp?productId=3549579&CAWELAID=351933682 I know Cub foods carries it in your area.
http://householdproducts.nlm.nih.gov/cgi-bin/household/brands?tbl=brands&id=3005022

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That's the stuff I use. It goes a long way, too... I've been using the same box since 2007.

Good luck.
Cheers,

I'm with nteeny on the printing vs scanning issue: if there are density differences in a scan, they should appear on a paper print. (My darkrrom will be reassembled in the next six months.) I did try filtering an initial batch I tried, so I'll try that again. The Caffenol blog recommends letting the mixture sit at least five minutes before using, and to use it before thirty minutes have elapsed. I don't mind the fog -- in a way, it's like the old technique of flashing negatives to cut contrast. But the uneven development is a bummer.

I think people are loosing sight of the ball on two issues as far as caffenol goes :

1. No need to buy the chemicals at the local mart. Its a developer, get proper chemicals of photo grade.

2. Nobody ever accomplished anything in science by being sloppy, do it properly or leave it alone. Caffenol C is a developer that works just as any else, but still can be tweaked further for superior results.

I'm experimenting with stand bottles with premixed single ingredients.

Soda will last *forever*, but get photo grade or face the consequences.

Vitamin-C is used to make other things last, and will last a long time in solution. Get Vit C powder not the tablets with all kinds of verid stuff in them.

Cafeic Acid which is the active ingredient in cofee will not last, but can be protected in solution the same way hydroquinone and Metol was protected, by adding 10% Sodium sulphite to the bottle, or Potassium Metabisulphite. Get the dark brown grade of coffee not light Nescafe...less acid in them.

If one follows that direction, adding a little Sodium sulphite, and going the route of a low PH mix, as published on the Caffenol Blog lately, the sodium sulphite will work as to stabilise the lower PH, making for better results.

Thats the theory, but it needs to be confirmed by several workers....

Having stand bottles prepared makes for an effective work-flow and was much used back in the day. You hjust load the developing tank, wisps out 3 stand bottles, measure 100 ml from each and mix them in the proper sequence : Soda + Vitamine C, let stand until the bubbles have subsided, to this mix add the coffe mix and let stand for at least 15 minutes, then develop.

Less hassle at the workbench when one prepares beforehand!

erik

what are the consequences for NON photo grade washing soda ?
i have used pharmacy grade as well as the arm and hammer grade
and noticed no difference at all.

how long have you been working with coffee developers ?

john

I've let the developer sit an hour or two and it still works fine. I mixed up a liter, got distracted and had to take care of some other stuff, came back to it some time later, and then took it into the darkroom. Developed 5 8x10 and a 4x5 negative in two batches with that mix over the course of the next hour.

I've noticed many people's time estimates are way too long, and they don't get instantly good results. You're going to need at least three separate rolls or sheets of experimenting to find what works for your agitation methods, temperatures, and ingredients. Coffee has more variations than wine, but fortunately the instant stuff is fairly uniformly vulgar if you stick with one brand and one variety.

I have the answer! (well it works for me anyway)

Pardon my exuberance, but I have been very much looking forward to reporting this. Like Trask and others I have been frustrated by the overdeveloped edges I was consistently seeing in all my caffenol-C developments (despite the fact that not everyone seems to experience this), and found this a debilitating defect in what would otherwise be a very nice, fun developer. But a couple weeks ago after a lot of experimenting I finally made a breakthrough!

First I should point out that I tried a lot of different things before finding a solution that worked for me. The obvious was to increase or decrease the amount of agitation. I went all the way from continuous agitation, down to stand development with no luck. I tweaked my recipe by varying the amount of soda, the coffee/vitamin-C ratio, and different dilutions, all to no avail. I experimented with different temperatures. I tried filling the tank completely, or leaving a substantial air pocket. I even tried adding spacers in the tank to immobilize the reel in the tank and limit its movement during agitation, but again the results didn't seem to change very much.

What I finally hit upon was a change in my agitation regime - not in terms of how long or often I was agitating, but rather how vigorously. With every other developer I have used, a "standard" agitation involving fairly slow, gentle inversions has worked well (for what its worth, 30 seconds initially then 10 seconds every minute following, is what I had settled on). But for whatever reason, my caffenol-C developer seems to need very vigorous agitation to avoid the enhanced development on the edges. And when I say vigorous, I mean cocktail-shaker style agitation! At first I mixed up the shaking to include a combination of rapid inversions, axial movement, and rolling and twisting motions. However I settled on mostly simple (but very rapid) inversions - basically inverting the tank back and forth end over end as quickly as possible - and stopping to rotate the tank every few seconds so as to avoid having the air pocket in the same place. I still use the same durations and frequencies of agitation as before. I just shake a lot harder!

With this vigorous agitation the developer does seem to get quite frothy. Fortunately, it doesn't seem to have any deleterious effects however. I should add that I have settled on not completely filling the tank but rather leaving a bit of air at the top to enhance flow during agitation. Whether this matters or not in the present discussion I don't know, but I thought I would mention it in case anyone wants to try to duplicate my technique.

So I am looking forward to having someone else try this - someone who is experiencing the edge development problem, that is. Let me know if you find this helps, or if I am just hallucinating.

Oh and for what its worth, I have also found that adding 5ml (about 1tsp) of salt per 500ml of solution substantially reduces the fog in caffenol-C. I tried sea salt at first but I have found that common table salt (good ole' Morton's iodized salt) seems to work just as well.

To reduce fog, I suggest using whats been standard in the industry since about 1890 : Potassiun bromide, KBr

100 gram to 1000ml (1 litre) allows you to just add 30ml (which then will contain 3 grams of KB) which is about right for 1 litre (1000 ml ) developer.

Yankees & britons with 12 fingers of course have problemt here, the rest of us that has 10 fingers and goes metric has less problems....

Being able to MEASURE exactly what one is doing is the only road to success and I recommend the caffenol blog, where this is explained in more detail by our german friend.

Erik Prestmo said:

Being able to MEASURE exactly what one is doing is the only road to success and I recommend the caffenol blog, where this is explained in more detail by our german friend.

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sorry to be contrary ...

you do not need to measure exactly with caffenol c.
you do not need to use vitamin c or washing soda that is photo grade.
AND you will not have "consequences to suffer" as you suggest ...

plenty of people use non photo-grade ingredients,
and had no problems.

I've worked with potassium bromide for fog control, and had some good results, but so far nothing reproducible. I have detailed notes on what quantities I've tried, but they seem to be hanging out with Jimmy Hoffa somewhere---whatever the exact numbers are, though, the point is that the same level of KBr will sometimes control the fog and sometimes not. (3 g/l as quoted above sounds high to me---I think that's the range in which I was getting thin negatives that scanned OK but probably weren't optically printable very easily.)

I suspect that the issue isn't the "grade" of the washing soda or ascorbic acid, but either the vagaries of volumetric measuring or (more likely) the variability of the coffee itself. It's not like you can get photo-grade caffeic acid!

I'll try the more vigorous agitation suggested by Denverdad above---I hadn't thought of that and it seems like a reasonable approach to me. Darn, now I need to go out and burn some film to have a test roll!

-NT

jnanian said:

sorry to be contrary ...

you do not need to measure exactly with caffenol c.
you do not need to use vitamin c or washing soda that is photo grade.
AND you will not have "consequences to suffer" as you suggest ...

plenty of people use non photo-grade ingredients,
and had no problems.

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I'm with John on this one.

Measuring the Foldgers, Arm and Hammer, and Vit C exactly each time as well as adding sodium sulphite/ potassium bromide kind of takes the fun out of "this" developer. Might as well skip the coffee and Vit c and add a little metol/ hydroquinone to the mix.:rolleyes:

The aroma of coffee is caused by several sulfur compounds called mercaptans or thiols. Unfortunately for photographers these same compounds are also very active fogging agents. No wonder that people are experiencing high fog levels with coffee developers. These developers are a parlor trick and nothing more.

Gerald C Koch said:

The aroma of coffee is caused by several sulfur compounds called mercaptans or thiols. Unfortunately for photographers these same compounds are also very active fogging agents.

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I'd be interested in more details. There are a lot of variations in sulfur compounds between different coffees, and I'm curious if you have a general source on what thiols are fogging agents.

Hydrogen sulfide is a foggant (is that a word?) and has some occurrence in roasted coffee, though at pretty low levels (and I don't know what level is photographically interesting). The source I went to (Flament & Bessiere-Thomas, _Coffee Flavour Chemistry_) suggests that a lot of the aromatic thiols are more prevalent in arabica coffees (which make a poor developer) than robustas.

These developers are a parlor trick and nothing more.

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I don't know about "nothing more". They're a developer that's capable of making negatives people like; I think it's quite reasonable to investigate how much the troublesome aspects can be brought under control. But I certainly agree that we're unlikely to see many pros developing their bread-and-butter work in coffee!

-NT

ntenny said:

But I certainly agree that we're unlikely to see many pros developing their bread-and-butter work in coffee!

-NT

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i processed a wedding in coffee
as well as a family portrait session.
my customers had no complaints ...

Thiols (mercaptans) contain the group -SH and can be considered tp be a substituted hydrogen sulide molecule where one of the hydrogen atoms has been replaced with an organic group. Taking the molecular weights into consideration I don't think that it matters much what the substituting group may be for determining the amount of fog produced. One compound in cofee is methyl mercaptan (CH3SH) which is also partly responsible for a skunk's smell.

Sulfur has a peculiar place in photochemistry. Sulfur compounds in the gelatine have a profound effect on the sensitivity of an emulsion and are actually needed to achieve practical speeds. However there is a fine line where too much of these compounds has a adverse effect. Some sulfur compounds in very small amounts act as antifoggants while others are fixing agents.