Depends on the chocolate you are using. If the chocolate is melting when you serve it and won't set up right, it probably isn't tempered. I wrote about how to temper chocolate on my blog..http://motherskitchen.blogspot.com/20... There's a lot of good info there...too much to reprint here, but it's a little more complicated than just melting it in the microwave . You need to hit the right temperature for the chocolate you have, you need the tempering curve for your specific chocolate. In general, though, for a dark chocolate it's probably 90 F. Usually high end chocolate makers have that info on their websites, but you are probably safe with 90 F if it is a dark chocolate.
Here's how to do it in the microwave....
-You need a good thermometer that measures temps in the 100F region accurately
-Use a plastic bowl for tempering chocolate - it retains less heat than glass. I have some Tupperware Rock and Serve containers that work well for me.
-To temper a pound of chopped up dark chocolate, microwave it for a minute and stir, and return it to the microwave for about 30 seconds and stir again, and keep doing this (reduce how many seconds you wave it as it gets closer to being done) until is about 75% melted.
-Once it's that far melted, just keep stirring it until it's all melted. Check the temperature....the goal is to get it to 90 F without going over.
-If you blow it and go over 90 F, all is not lost. Return the chocolate to the microwave and heat it to 115-120 F. Don't go over. Then add about 4 oz. of finely chopped chocolate that is already tempered (this is called seed chocolate). Bars of baking chocolate are already tempered, so that will work. This gives the cocoa butter some crystals of the already formed chocolate to glom onto. Remember back in high school chemistry where you made crystals? No, of course you don't! Anyway, what you learned and forgot is that crystals beget other crystals. Once a crystal has formed, it's easier for others to form on it. Crystals need friends!
-How to know if your chocolate has tempered? Dip your finger in and smear it on a piece of parchment paper. It should set up and get hard in a couple minutes. You can put it in the fridge to hasten the process. If not, go back and do a redo like described above. Chocolate is very forgiving.
Those are great directions--a lot of good information. I heat chocolate on the stove, but like the seed method. I've never used a double boiler and haven't had problems. I think the newer stoves allow for lower constant temperatures and as long as I'm diligent, don't worry about it. The possibility of seizing the chocolate keeps me away from the double boiler. A candy thermometer, or at least a quick read thermometer, is very important, imo.
The biggest problem I have is keeping the chocolate in temper while I'm dipping because if I'm doing enough, it cools down. So, while the first batches turn out fine, eventually, I get just dipped chocolate. Alton Brown suggested using an electric heating pad but I haven't tried that yet. But, this won't be a problem for chocolate bark.
First, yes, you should temper chocolate when making bark.
That said, if the bark is melting in your hands, I don't think it's because you are not tempering. I think the problem is either the type of chocolate you are using, or you're not letting it set long enough before eating.
By the way, you might have more responses if you post on the Home Cooking board.