I'm working on a little project and need chocolate powder. Not the one you can drink, it should be real chocolate but grinded. I tried using a coffee grinder, it gets to warm and starts sticking together. It has to be about as fine as sugar.
Does someone have any suggestions on what to try next?
Chocolate isn't suitable for grinding. Get a fine enough grating tool and grate the chocolate by hand. The suitable tool is either a hand-rotated drum grater with a fine drum, or a flat Microplane-style grater. Start with fridge-cold chocolate (freezer is likely too cold). You'll get little commas rather than powder, so try stirring it a bit to break up the pieces even finer.
Alternatively, you can use a food processor, again on fridge-cold chocolate. To avoid the melting problem, do it in single pulses. The problem here is that you'll probably end up with pieces larger than crystal sugar. But else, it does quite a good job of chocolate, I use it sometimes when I need to finely disperse chocolate for finicky couvertures and similar.
If you freeze a mortar and pestle and some chocolate, you should be able to grind the chocolate to powder without melting it or making it stick together. Depending on the ambient temperature and the heat capacity of your equipment, you may need to re-freeze it halfway through the process. I would not try this in a warm room. If it’s cold outside where you are, do it outside.
Dark chocolate will be much, much easier to grind than milk chocolate.
You can possibly add maltodextrine to bind the fats and make it powdery. I would try this with frozen chocklate in a high power food processor with pauses to avoiding overheating and thus melting, but you could possibly use the melting in your favour, too
