Stir Bars

So I made a stir plate recently, tested it out with a magnetic bar I had, and it works great. Well now I am buying flasks and stir-bars, so a bit of advice I thought.

Stir bars - I know they are cheap and easily found, but what about the cross ones, do you guys prefer those over a standard straight stir bar?

Flasks - Wide Mouth vs Narrow?

 

Never tried a cross one, but between my 2" and 1 " bars, the smaller, lighter bar works better.

As far as wide or narrow, how wide are you going? I would think narrow would be easier to get a foam stopper for.

 

I use a 1" straight bar, and it works great! My flask is a 2L mason jar and I use foil on top.

 

What's the best speed? A strong vortex, or just lightly stirring?

 

All you need is a little bellybutton sized vortex. Slow and steady.....

 

+1 on above. I have a 1" stir bar and turn it on the slowest setting. The purpose of a stir plate is to circulate the yeast so they all get maximum contact with oxygen at the top of the vessel. Faster is not better. I would be concerned that a larger stir bar may encounter increased resistance and be more prone to slinging off the magnet.

 

Thanks much, I didn't really think the cross ones were necessary, I'll go with a little pack of some smaller ones.

I'm not really sure with how wide or narrow, just the sets of flasks I was looking at were wide and narrow mouths, I wouldn't reckon it to make much of a difference, but best to ask those with experience rather than rely on theory alone.

 

+1 I bought a 2 inch thinking I would make this swirling tornado of killer yeast and I quickly learned that none of that is necessary. I only fought with it..

 

I spent a lot of time getting a 2" to spin. I do think it works a little better than my 1/2" in my 4L flask, but really not a lot better. In a smaller flask the 1/2" would be perfect.

 

I got a couple of the puck looking ones. It does well but not so much better that its worth the extra money

 

i guessing general consensis is that 1" is better than 2". I have a homemade stirplate and my 1" would get thrown once the yeast was thickening up so i would have to reset it ever 4 hours or so. I lost the one i have and was thinking a 2" would be better but now im second guessing it.

 

I have a home brew stir plate and have never had a problem slinging a 1" stir bar even in a 1.7L starter at high krausen. Perhaps I can offer some suggestions?

 

Well, my first starter (1.5 in a 2L flask) foamed out of the top, lol. Guess I won't try to push the volume next time.

 

I use a 1.25" stir bar in several different beakers, from 1L flask to juice bottles. Works great all the time. Key is having a variable amp (=speed) power supply. I start slow, get the bar spinning properly and then amp up until I get a little whirlpool action. I have left this running for two days and never thrown the bar (forgot I had it going...homebrew can do that to you sometime ).