Good quality stir bar, but the ones I received did not have the rib pictured. The rib helps the stir bar from getting stuck to the bottom of the flask.
It looks like I'm not the only one. I accidentally destroyed my previous stir bar (different product) in the garbage disposal, so I picked this one up. I had no issues at all with the previous one but I just can't get this thing to stop making a godawful noise. It gets 2 stars because it does its job, but I can hear this thing spinning across the hall through 2 closed doors.
Unfortunately, the little ridge in the middle of this stir bar creates a loud annoying rattle. Tried re-centering, high speed, low speed. Nothing works.
The smooth hexagon one that originally came with my Hanna Instruments stirplate does not have this issue.
I guess it's not a big deal, but i build my starters indoors and can't deal with the noise.
This stir bar works in my 1000ml flask all the way up to my 5000ml. Originally bought this as a back up but I have since made this my workhorse stir bar.
I've used 2" bars and bars with the "stabalizer ring." The ring only makes the bar clang all the while it's spinning and the larger the bar the more frequently it gets thrown. These 1" bars are perfect and can work at higher RPM of the other bars. Can't beat em'!
I used this to replace a larger (2") bar I'd been having trouble keeping on the stir plate. This is a better fit, for my stir plate at least and works great even in my bigger starters
I use this in both my 1L and 2L flasks. Easy to clean, stays where I want it in the flask. Keeps the starter humming along. Tip: use a small magnet on the outside of the flask to hold the stir bar in place when you dump your yeast into your fermenter.
I use this on the Hanna stir plate that More Beer sells usually with a 5L flask. I've used it on starters up to 3.5 liters and it gets that volume moving well.
I use this size in my 2Kml and my 1kml flasks. I always keep a back up stir bar. Once it goes in the fermenter (accidentally) then it will have to stay in there.
I use this when I make smaller yeast starters, works great, would recommend this to anyone. Easy to clean and have used this for over 2 years with no problem.
Don't be fooled into thinking that you need much more stir bar than this. Easily stirs a 2000ml erlenmyer. I have several sizes of stir bar and this is the one I reach for 90% of the time
I have used this for my smaller starters (up to 1.5 liter) and even used this in a 1 gallon mead batch. A 2" would have worked better with the mead, but it wasn't thrown and it was in use for a month strait.