In my quest for a good coffee juice, I’ve done it a couple times. So far, not so great juice, but the flavoring smelled amazing. It was a little messy, but that’s probably because I didn’t have glass bottles so I had to use a cup.
The first time I did it with good coffee, but I messed it up and didn’t steep it or heat it. Then, my brother accidentally dumped it all over the counter while it was filtering. That time I used a coffee filter clipped to a cup. The second time, I did it with my grocery store’s brand of caramel macchiato and it smells and tastes good. I used an aeropress to filter it and just ran it through a couple times. Seemed to do a decent job. I’ve still got it and still playing around with it. We’ll see.
I’d definitely recommend anyone who likes coffee to try it and post your results here for the rest of us. At worst, all you lose is a couple tablespoons of coffee and some PG.