DIY Carboy Stirplate

I've recently done a major upgrade to the size of my brewery to where I'm usually doing 15 gallon batches, but my big fermenter is 200L (53 gal). A double brew day means I can put 37 gallons in there. If that's a lager, it means a HUGE starter. I've built stir plates before, but I don't think that design would work well with a 5 gallon carboy.

I've read a lot of posts where someone asks about it, but it's mostly to spin during fermentation and it's shot down due to oxygen during fermentation. This isn't a concern for a starter.

Does anyone have any suggestions on how to build a super heavy duty stir plate for this? What about a motor on a bucket with paddles? Submersible pump in a bucket?

Just curious what people think. Thanks!!

 

Why not just make a 5 gallon batch of your favorite lager so you don't throw away what is essentially a batch of beer? I don't see why using a motor with a paddle setup wouldn't work. Maybe get a gear motor and hook up a SS wine degassing wand to it. I would be hesitant to do a standard stir plate as a carboy doesn't have a flat bottom so you would likely end up having it spin off all the time, and a stir bar might wear through a plastic bucket. If you can get a food safe pump, that seems like it might be capable of creating a necessary whirlpool...perhaps an aquarium pump with a magnetic impeller drive?

 

Check the DIY forum. I know I've seen a lot of pictures of stirplates pulling vortexes on carboys.