You will often find that moka pots brew stronger coffee than the standard drip coffee makers. If you want to avoid bitterness, there are several things that you should do. For starters, choose the right grind of coffee. An expert in your local store can probably recommend a type worth trying. Many advanced coffee lovers will tell you to go for coarse grinds. Next, feel free to experiment with the ratio between coffee and water. It is also important to get the heat right. It will take a bit of trial and error the first time you start using a moka pot, but once you figure out how to brew a perfect cup of coffee without any bitter hints, you will be delighted.