Originally Posted by Newsman
Can one use something like a bolt (with the head cut off) covered in heat-shrink tubing instead of buying a "stir bar"?
I will give a definitive No, because the object on top has to be magnetized, otherwise you will have unpredictable spin patterns, and that will cause all sorts of problems. Just pony up the 4$ for the stir bar... it will be worth it
Also make sure you get a stir bar with a pivot roll in the center. It will make the spinning a lot easier, and when the yeast starts to build up you will have problems with it if you dont... That is the problem I ran into, now I have a bar with a pivot and its great.