Alright, gang, as promised, I've done the coffee dyeing experiment!
The photo essay is available on my
Flickr Photoset: Dyeing Coffee Rags, or you can read on for further narrative accompanying the photos.
I started out with about 3 days of coffee pucks. I've been consuming more coffee than usual (4-5 doubles/day) as a result of the mystique of getting a new grinder, so this is a good bit. My Bumper knockbox was nearly full. In addition to that, I purged the remaining coffee from my grinder, which was a little less than a double shot's worth of coffee.
To speed things up, I started out with water from Vetrano:
Fresh grinds + Boiling Vetrano water, awaiting the addition of the pucks (lower right).I gathered my rags; I planned to do four of them, in various states of usage as you can see below:
I loaded up the rags into the pot...
... drove them down ...
... and away I went to boil them.
I wanted to boil them for an hour, but I ended up having to settle for just 45 minutes, as we had to go out. After the 45 minute boil, I turned off the heat and left them to sit for about 2 hours while we were gone.
Upon my return, I was greeted with a sludgy mess of rags.Cleaning them off was a real pain in my sink, and I would strongly suggest doing this outside in a garden with a hose, if you have the means. If you must do it indoors, as Chris said, make sure you have a way to filter the grinds to prevent the lion's share of them from clogging your U-trap. It's a LOT of coffee grinds to go down at once.
What a mess!After wringing out as much of the coffee as possible, I put the rags in some ice water. I guess I was thinking that the hot/cold contrast would help set the color best:
After the icing, I wrung them out some more, and then boiled them again, this time in plain water, for several minutes. One more bout in the ice, and more wringing:
... and I was ready to wash them. I put them in the washer twice, first on cold, and then on hot, and then dried them. The results:
The control rag. This is one of the used rags that I didn't dye, for some comparison. Note it's stained and not perfectly white.
This is the one dyed rag whose stains didn't get covered. This particular rag was used to wipe out some burnt coffee oils from inside the grouphead to expedite the backflushing process (and get some stuff it just can't get). You can see these stains are much darker.
Finally, one of the rags that came out quite nicely. The other 3 looked like this.As you can see, they are fairly light when dry. The pictures above make them look a lot paler than they look in person, but you get the idea. Wet, they look almost as mocha-dark as the above image of the rag before washing, but after a thorough wringing out.
Here you can see the rags under my sink, where I keep them:
The bottom rag is undyed... you can see the contrast a little better here. And here's a parting shot of a damp rag on my countertop next to my setup:
Somewhat darker when wet.I enjoyed the process, and I think I would do it again. If I were doing it again, I would change the following:
- Bigger pot + more water. There's a lot less work involved if you have enough water for the rags to get swished around on their own in the rolling boil of the pot.
- As I mentioned before--Rinse off the rags out of doors. It's a pain to keep the coffee grounds from clogging your sink--there's a ton of them!
- Use less coffee. Judging by how this run went, I think I super-saturated the water. I think it would have been equally effective with half the coffee (or twice the rags).
Finally, I think it's worth considering multiple iterations. I am curious if I can darken these rags a bit more by doing this a couple more times over the next while. I think the work will be minimal with the changes I suggested above.
by Psyd on Tue Nov 25, 2008 4:38 pm 
