Beer Forum

So a friend of mine who works in a lab got me a industrial stir plate and I cant seem to get the stir bar to spin in place... I start it out on the very slowest setting and the bar just bounces around in the flask (5000 ml) with water in it. I have noticed that the bottom (outside) of the flask is slightly concave.. could this the problem??

The stir bar spins fine alone on the plate.. Any help on this would be great

They make a barbell shaped stir magnet that might work better on the bottom of your particular flask.


Mylo

I have one of those stir plates. Make sure you have the stir bar that is about 1.25 to 1.5 inches long. Mine isn't a barbell but I have also heard those work well. The longer cylinder ones seem to center fine for me. I haven't had much luck centering the stir bars that look like little footballs or little pill capsules.

The other thing I do is take another magnet and center the stir bar in the flask from the bottom. I just move the stir bar from the edge and move it to the center right before I set it on the stir plate.

Using an external magnet is also a good way to get the stir bar out of the flask before pitching. I have never dumped a stir bar in the fermenter because I always pull it up the side and out of the flask before pitching.

Hope that helps.

Yeah, that's a problem with those things.

Starting off slow is logical, but isn't the answer. Make sure the flask is perfectly centered and crank the puppy up about 3/4 speed to start. It'll take two or three tries to get the speed right. Once the bar and liquid are moving reduce the speed to where you want it.

The things will still hic the bar occasionally. It might have to do with the bar losing its magnetism, a lack of molecular affinity or a plague of mice. I dunno.

Charlie

Having wort in there will slow things down, too. It really makes a difference.

Charlie wrote:The things will still hic the bar occasionally. It might have to do with the bar losing its magnetism, a lack of molecular affinity or a plague of mice. I dunno.

Charlie

I've heard of that!!!

The molecular mice plague, the end of days is nigh!!!

I'd try a longer stir bar like someone mentioned. My flask has a convex bottom but it doesn't affect my stirbar because it's about an inch and a half. Good luck.

Chris_J wrote:my stirbar ...it's only about an inch and a half

No wonder the canadians have a little brother complex