After much chatter about this question, I must admit that I've become a little obsessed with this concept. Maybe a lot obsessed...
Concept. I see three other possible ways of making a jam/conserve/preserve/marmalade/jelly/... out of coffee fruit (i.e., coffee berries / coffee cherries) or coffee cherry husks (by "husks" I mean basically the fruit with seeds removed -- everything except the beans), in decreasing order of actual coffee fruit content:
- Use the whole fruit (possibly with seeds and all), so as to make a conserve;
- Make something like a jam or marmalade, using the shredded, dried, rehydrated husks;
- Infuse the husks as cascara, discard the spent husks, then make a jelly out of the resulting brew (tisane).
Exclusions. Note that I am not including coffee jelly, which is made of (conventional, roasted) brewed coffee, as noted previously; also not including making a jam out of roasted or un-roasted coffee beans themselves. Both of those are interesting concepts, but discounted here to be left as separate topics.
Progress! I searched a bunch for a source of any coffee cherries or dried husks. Amazon didn't even seem to sell any (must have been my error!?). I asked around at a few local coffee shops, with little progress. I found a few pages, like this one and one from a NYT blog that gave a glimmer of hope that husks (at least) could be found. Both of those articles point to Counter Culture Coffee as selling these, but they're not in stock. An immensely helpful person from CCC pointed me to Verve Coffee Roasters, who sell coffee cherry husks for cascara. So as to get my lot before the rush on coffee cherry husks that would undoubtedly come from this post, I ordered some. Since I'm having trouble being patient and waiting for the stuff to arrive, I started...
Seeking Seasoned Advice! With all due credit to OP @EricPlaton, I posted a question over at Seasoned Advice about the concept of making jam or preserves out of coffee cherry husks or whole coffee cherries. I wrote a comment about this above, but I still hope OP doesn't mind!
More to come, and any comments or suggestions are kindly welcomed.