Stirbar/Flask

What is a good source for Stirbar/flasks? stirbar.com has quite a variety. What length/shape is recommeded? All they seem to carry are polypropylene flasks. Will that work? Where can I get a glass flask? Is 2000ml the recommended size?

You could compare Cynmar.com. I thought they were reasonable. You want either Kimax or Pyrex. 2000ml is preferable unless you only brew 5 gallon batches of small ales under 1.040.

The strength of your magnets will play a part in how large a stir bar you can use. I built my own, similar to the threads on HBT, and it throws the standard 2" stir bar but the 1" bar works just fine.

A 1" standard bar is the safe bet. Anything larger and/or differently shaped may be too much for your magnets to handle. It all depends on how strong they are.

Without hijacking this thread way too much i've got a few questions here myself.
On an Imperial Stout should I make one like "Tom Mike's with an OG of 1.108-1.109, FG 1.030-1.031 ABV 10% what size flask in ML should I use for a starter for a 10 gallon batch?
Other question; I have a few rare earth (NEO) magnets that are 2" x 1/2" x 1/4" thick strong as hell to pull two of 'em apart. Would one of these work on a 4" computer fan motor to turn a stir magnet? Now what size stir magnet should I use? I know the distance between magnets should be close as possible. The fan will have a electronic speed control as posted on this forum in the past. Now back to the OP question, sorry about the hijacking just didn't want to have the same questions asked over again with another new posting.

cdburg said:

The strength of your magnets will play a part in how large a stir bar you can use. I built my own, similar to the threads on HBT, and it throws the standard 2" stir bar but the 1" bar works just fine.

A 1" standard bar is the safe bet. Anything larger and/or differently shaped may be too much for your magnets to handle. It all depends on how strong they are.

Click to expand...

My 2" stirbars don't seem to center on the magnets like my 1" and .75" does so mine get thrown also. I wonder if there is something up with the 2"'ers

Here's how I solved my stir bar woes - copy of a couple of entries I posted on the Aussie site:


After building a stir plate much like all the others you read about on these forums, getting the bloody stir bar to mate with the magnet and stay on was a PITA.
Tips from what I learnt the hard way, in the spirit of sharing:
Make sure you can start your fan with the stir bar in place from a standing start. Changing the fan worked for me.
Get an Oval shaped stir bar. After spending hours with cylindrical bars of different sizes, with and without rings, the oval one worked right away !and stayed on!. It seems quieter too. Probably more significant if your flask has a slightly convex bottom. More expensive by a few bucks.
There you go.
AND
The thing is to make the stir bar equal or slightly less than than the length of the magnet. I use one magnet on top of the fan. Not sure how you would go with two magnets - but suspect it might be even more stable, and a larger bar would sit within them. Mine is a 30 mm length bar, I think about 16mm at widest point.
I don't think I will need more than one bar. The speed control would allow you to adjust for diff size starters.
I suggest you get a 5 litre erlenmyer. This would allow you the flexibility to make larger starters for high gravity brews and allow some head space. Mine stirs 4 litres nicely. You don't have to pull 10 gees, you just have to keep the yeast moving in suspension.
One a recent Sunday Session podcast on the Brewing Network, the White Labs guy was on, and mentioned that a 1 litre starter with 1 vial/smack pack will only take your pitch numbers up 125% (hardly worth it), whereas a 4 litre starter would be 280%, and that for a regular gravity brew you would do a 2 ltire starter normally.
Also, try and get a flask with as flat a bottom as possible - choose amongst the batch. Not a huge deal, as mine is significantly convex, and i just spin the bar a little off centre.
Do you need more than one? Well, my funnel traps the Oval bar in the neck, because it is so wide, when I pitch from the flask to the fermenter.
If you couldn't recover it when doing so, and you wanted to do a brew before the fermenter is free again, then yes, you would need more than one.

Based on the the great info you all have provided, I ordered a 2000ml glass flask and 2 - 1" stirbars. I'm going to build my own stirplate so I'll see how it goes. Thanks all!

See my stirplate and stir bar here.http://www.footballbrew.com/homebrew/video/Video0005.mp4

The 1" oval stirbar works great. Once I got the magnet centered on the fan, the stirbar stays right on track. Works perfect with a 12vdc wall transformer.