Developing film with coffee

Developing film with coffee sounds like a line from Peter Kay’s standup routine. Cheese….cake? Developing film?…..with coffee??

oh yes, developing film by using instant coffee and other ingredients readily available in Tesco can be done.

There’s a lot of boring chemistry I don’t understand, but the gist of it is that black and white film has elements of silver that react to light. Turning those into a picture uses chemicals ….or coffee.   Within caffeine there is a chemical called caffeic acid, which acts as the developing agent when it reacts with silver.   One of the other ingredients, washing soda, acts as the accelerator because it raises the PH level suitably high enough for the developing agent to work.   And then finally the vitamin C works to further accelerate the developing started by the caffeic acid (using that alone would mean you had to wait hours for the film develop, adding that mega dose of ascorbic acid makes the process speed up).

You can’t drink the coffee after, which is a shame but you can sit back and look at your negatives, and think “wow, I really did it”

What do I need to buy to develop film with coffee?

First, you probably need to go shopping.

Some of this stuff is optional but it’ll make your life easier.

And don’t use this for your once in a lifetime shots – this is really just an experiment. Something you could do with the kids for a bit of fun maybe?

1) Changing bag. This is a light-tight bag that looks like a t-shirt with no neck hole and a zip across the waist bit. It also has lined, elastic aged arms. You could make one, or you could just work in the dark (but ideally you want it totally dark so a blackout bag is advisable).  You can get them on Amazon, here: Dark Room Changing Bag

2) Film developing tank. Again, if you’re in a completely dark environment you could use open tanks but a made for the job tank is so much easier.

3) Clothes pegs

4) Scissors

5) Bottle opener. No idea where you’d find one of those

6) Scales

7) Two measuring jugs

8) Vitamin C (you can grind tablets for this)

9) Instant coffee

10) Washing soda crystals. DriPak is good for this and cheap. Available in many good supermarkets.

How do you develop film using instant coffee?

Step 1

Put the following things into your light tight bag and zip it up: scissors, bottle opener, developing tank and your black and white film canister. Put your hands in the arm holes and make sure you can find everything. Now open the canister using the bottle opener.  Just imagine it’s a bottle of beer 😉

From now, don’t open the light bag until you’re sure the film is in the developing tank and it’s sealed. Don’t rush and don’t worry. You can reload it if you need to.

Take the film spool out of the canister and unroll the film, eventually you’ll get to the other end, where it’s looped into the spool.
be careful with the next bit because the film has a natural curl in it.
Making sure that you only have that bit (where the film meets the spool) in your hands, cut it free from the spool with the scissors.

You now have exposed film in your hands and a tank to get it in. Don’t open the bag.

The next bit you have to do by feel so this is what you would see if you could see it:

Put one end of the film in the notches on the developing reel and feed the film in slowly. Take your time, it’ll go but it’s snug and can be fiddly. This may take several minutes.

Because the film has a curl, you’ll find it easier to work *with* this curl. Eventually it’ll go in and will look like this (but you can’t see it because you haven’t opened the bag!)

Once the film is in the reel, pop the reel in the tank and close the lid.
Check this twice by feel to make sure it’s on properly.

Now you can open the bag and take the tank out.

Step 2

Tip: once it’s outside the bag, check the lid by eye. If it’s not flat, not on right, put it BACK IN THE BAG and undo/do it up again.  Once you’re happy with it, you can think about developing it.

Exact measurements are as follows:

For a 35mm black and white film

  • 45g Soda Crystals
  • 4.8g Vitamin-C powder
  • 12g Rich Roast Instant Coffee
  • 3.6g Iodized Table Salt
  • 300ml of water

For a 120mm black and white film

  • 90g soda crystals
  • 9.6g vitamin C
  • 24g coffee
  • 7.2g salt
  • 600ml of water

Method for developing is as follows

  • Fill the first jug with half the final volume of water. ie if the end goal is 300ml of solution, then fill with 150ml of water for a 35mm film; or if you are developing a 120mm film then 300ml of the 600ml required.
  • Add soda crystals and stir for a couple of minutes until completely dissolved.
  • Pour in the vitamin C and stir until the fizzing stops.
  • Pour in the instant coffee granules and stir for about a minute
  • Pour in salt and stir again.
  • Top up with enough water to make the amounts as stated above (ie the remaining 50%).

Ideally you want this brown sludge to be around 20 degrees so if you have a thermometer that would be great.  You can either add warmer water in the second amount or you can stand the jug in a bowl of boiling water until it gets to the right temperature.

Into the second jug make up a fairly weak solution of salty water.

Step 3

Get your brown sludge and pour it into the developing tank and gently tap the tank on the work surface to dislodge any air bubbles… you want the solution to cover the film evenly.  This next bit takes about 15 minutes.

Agitate the  tank every minute to move the solution around a bit.

After fifteen minutes or so, pour the sludge out.

Step 4

Don’t open the tank.

Pour fresh water into the tank and agitate the tank for a couple of minutes.

Don’t open the tank.

Pour it out, repeat twice more.

Don’t open the tank (did I mention that?)

This water washes the developing mixture off the film, it’s called ‘STOP’ in film terms.

Step 5

Now, pour your salty water in and agitate the tank again for a couple of minutes. This is called ‘FIX’ and this effectively locks the picture…..eventually.

The film needs to sit in the fix for at least an hour.  There’s little point in trying to rush this, and it can be best to leave it overnight.

When you remove the film, you can look at it and see if you got anything useable.  You *can* look as soon as an hour after you start the ‘fix’ but tbh I think I’d leave it.  The film needs to be fixed for a few hours minimum so there’s little to be gained by peeking early.

Step 6

Once it comes out of the fix, You have to dry it, hanging freely in a damp room (bathrooms are good) so that it doesn’t dry too quickly. This is where your clothes peg comes in useful.

Check for Crystals on the film from the salt. This isn’t good so rinsing at this stage is probably a good idea .

Peg your film up to dry.

Can you tell who it is yet?

And there you have it.  A roll of film you developed using coffee and a few other household ingredients and no harsh chemicals!


Featured image of cameras  and coffee courtesy of Shutterstock

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