DetailsAn extra stir bar is a good idea in case you are doing more than one starter or as a backup. These things can get lost down the drain when cleaning out starter flasks after being pitched into a primary fermentor.
- Details & Instructions
Height 2" Diameter 1/4"
3.0 / 5.09 ReviewsWorks better at lower speedI have a 5 liter lab grade Erlenmeyer flask and bought this because I make big starters for lagers. At full speed on my stir plate I can make a huge vortex, though the stir bar occasionally gets thrown to the side.December 15, 2013stir barsStir Bar w/ Center Ring _x000D_I use two of the vortex with 2-1000ml flasks with the yellow ridge stir bar, in each._x000D_I start on high, which starts a strong vortex, then turn dow to maitain a strong stir, and it works great. Start both 24 hours before pitch, and in less then an hour, I have very strong activity._x000D_Use 3-7.5 and 1-5.5gallon, buckets for primary, for red wine, then transfer to 100 liter SS tank, for 3+ months, seconday on 1-poundof blended oak cubes.July 2, 2014Generates a large vortexI use it in a 5 liter flask at moderate speed so it doesn't get thrown. It stirs up the entire bottom so the yeast stay in suspension.February 18, 2014wasn't a huge fanDon't know if this is a result of my shoddy homemade stir plate or this stir bar but I didn't have much luck with this guy. It spun off more often than I liked making it uncomfortable to use when I am wondering if it is going to work. I bought another one with the ridge in the middle and had more luck.November 24, 2012Use it at low speedAt low speed it doesn't get thrown as easily, at high speed it gets thrown in a minute. For the 5L flask, place it off center so the hump isn't directly under the stir bar.November 28, 2013Doesn't WorkI agree with the previous review that this doesn't work. But not for the reason he suspects. The magnet does not have two fields as he suspects. Even it there were two magnets, as long as they are aligned north to south, it will act as one field. The problem is that in order to work, the magnet inside of the stirrer base has to be the same length as the stirrer bar. Since most stirrers use a 1" magnet, they have a 1" internal magnet. I took mine apart to confirm this. With a 2" stirrer over an 1" internal magnet, on pole of the longer magnet aligns with one end of the shorted internal magnet. The other end then overhangs the internal magnet by one inch and is therefore off center. When the stirrer starts, the long stirrer bar spins off center and flies to the side of the flask. It would work if you modify the internal magnet(s) to 2" spacing but probably not worth the effort as the 1" works fine.February 8, 2011Keeps getting thrownI got it for a 5000ML flask but it's not working out, it keeps getting thrown, and I've gone back to the small stir bar.September 15, 2013Get the small stir bar insteadThe big one ends up getting thrown all the time. And the small one works great , at low speed, in a 2ML flask._x000D_I've not tried a 5ML flask, maybe it would be useful there.October 25, 2013Poor DesignI may have received a damaged unit, but the one I received had two magnets inside and thus was a waste of $9.95 +S/H._x000D__x000D_In order for a stir plate magnet to work it must be one magnet, with only one north/south magnetic field. Like this_x000D__x000D_N--------S_x000D__x000D_If the stir bar has more that one magnet, it will have two field, like this. _x000D__x000D_N-----SN-----S_x000D__x000D_This is the magnet I received. Since the stir bar had two fields it was unable to center on the stir plate. The stir plate magnet will grab onto one end and spin the magnet off center until centrifugal force cause it to spin off the stir plate magnet._x000D__x000D_December 6, 2010
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