Back to Shopping at

DIY Stir Plate I built (video link)

I saw on YouTube that it’s pretty common to build your own stir plate, so I gave it a shot.

• Fan from an old PC
• An earth magnet from a defective hard drive
• The 12v DC power supply from an old wall charger
• A junk DVD player for the case
• An on/off switch.

Inside, I mounted it to a scrap 1/2-inch board with nuts, bolts and washers. So, I built it for a couple of dollars, basically.

I was wondering if I could place my primary (glass carboy) fermenter on this for an hour to oxygenate a newly pitched brew?

Watch the video - YouTube Link:


Nice job Kenneybellew.I like that you recycled your DVD player.
I also recycled some anceint video equipment.


I was thinking later, I wonder if I could have glued some magnets onto a permanent DVD and just pushed play - ha!

Nice build. Right away when I read your parts list I wondered about not having some sort of potentiometer to “start” the bar up. Most builds I have seen in the past w/o a speed control would only throw the bar instead of get it spinning. Does the fan automatically start spinning slow or something? Or does she just “catch” naturally?

“I could have glued some magnets onto a permanent DVD and just pushed play - ha!” That would be a trick nice mental image for the day!! love it.

Here also is some more stir plate Pron.
I used a $2 project box, 2 old hardrive magnets, 1 scrap muffin fan and an old sweet train controller that has 1 constant AC and 1 constant DC outputs PLUS a variable DC output controlled by the inboard potentiometer, super simple build as close to “plug and play” as you’ll find for under $10. I was all studied up into what parts I needed such as a potentiometer etc… And it dawned on me that I had an old train controller buried in some stuff. VIOLA:

Sweet setup.

I just added the potentiometer back. I’ve learned a couple of things. The stir behavior is different depending on the amount of water you’re stirring. More water equals more resistance. Less water equals potentially too much speed. Thick DME adds resistance.

I added the potentiometer back into the mix when my magnet kept flying off center in the flask. However, then I decided it was because my magnet on my fan was warbling due to the Velcro coming loose. I super-glued a big washer onto the fan (attaching the magnets to it) and that fixed the problem. So, I don’t recommend using Velcro (as I saw recommended in some video).

Right now, I’ve got a 1 gallon jug with a liter of fluid being stirred. The fan speed is much slower with that much fluid. I do not have a vortex like I did with the 1000 ml stir. This makes me want to get a more powerful fan.

Pheeww, glad to hear about the speed control. I thought maybe you found a easy way or something, maybe a groovy power source that mystically just started the fan slowly. LOL

-1 The only thing I keep seeing in my minds eye now is the scary sight of a full carboy squashing your new stir plate all to shite.

On the vortex thang, dont change a thing it will work perfectly fine as is. You really dont need a whopping tornado going on to do what is needed. Just a nice spin o roo is all them yeasties want my man.

Here it is being used for the first time. It’ll be interesting to see if I can get it to work with a carboy today when I brew the Belgian Golden Strong Ale.

Unless you have a big stir bar and some really powerful magnets, probably not. Mine can just barely turn 5.5 gal of wort, but I used some really burly rare-earth magnets. And that’s in a plastic bucket.

I’d stick to splashing/spraying the wort into the fermenter, and/or shaking it for a couple minutes. The DO level is the same either way, and I’m guessing it would take a long time to reach saturation just by stirring. Actually, if you’re going to keep fermenting in glass, I’d look into a pump/filter/stone setup. Carboys scare me.

You’re probably right. I do have a big stir magnet (2-inches) and powerful earth magnets on the fan, but I think my fan is too wimpy to churn that much fluid. I’ll give it a try today to see.

Back to Shopping at