Nope. Not a must, but certainly does help the beer clear a bit. I started without one but added a secondary just to see if it would make a diffeence. I believe it did so when I rebought equipment(been out of the hobby for a bit), I got a secondary too. The important thing is to make sure you dont have the beer in the primary for a long time so that it gets off tastes. If you dont have a lot of time for instance... you rack to the secondary and then bottle when you get the time without worring about off tastes. As with everything time is always on your side