when ever i make chocolate mousse it comes out all lumpy when i add the egg yolk to the chocolate. why is this?!

Best Answer - Chosen by Voters

You need to let it cool down and mix the egg before hand and mix it fast, preferably in a mixer

As another answerer said you need to temper your yolks. If you don't temper the yolks, they cook and get lumpy. To temper: Beat the yolks and add a small amount of your hot chocolate mixture into the yolk mixture, mix well until incorporated. Continue to add small amounts of the hot chocolate mixture until the yolks and chocolate mixtures are near the same temperature, then mix the two together. Hope this helped.

You aren't tempering the hot melted choc into the egg and are therefor curdling it.