Let's Talk Stirplates

[flyangler18]

So, I've got a stirplate that a buddy cobbled together with a wall wort, fan and cigar box. It spins a 375mm bar in 500ml of starter wort without difficulty, but I'm getting tired of stepping up starters using my dinky 1000ml and a 2000ml flask just seems to be too much for this stirplate. So, I'm looking around at surpus lab equipment to get something more heavy-duty for building up large starters, ideally with a bit of heat control for maximum growth. I like the DIY approach, but I honestly want something I won't have to upgrade down the road. Actually plating strains is something in the near future for me as well.

Reputable names to keep an eye out for? I know we have some members who work in labs with this stuff all the time (I'm talking to you, Pseudochef!), so spill it!

I've seen a number of these floating around on Ebay:

 

[HenryHill]

I got a Wheaton Biostir Model II, for $15; 8"x8", in perfect, like new condition, in an online auction-Ebay, IIRC.

It pays to search and wait. I put a 4l flask 3/4 full on it with a 1" stirbar and it works great.

 

[flyangler18]

Sweet, that's my kind of stir plate!

I'll have to keep my eyes peeled. Like I said, my current stir plate is still plenty usable, just looking towards the future.

 

[saq]

I'm also looking at getting a hot stir plate. It would be a great way to get the boiling out of the kitchen, as well as temperature controller your yeast reproduction (to say, 78f which is optimal) while stirring it up.
Seems to be $200 is the least you can get away with spending on one to get a 7" surface area for a 4L+ flask.

 

[mmb]

If you have any ties to your local school system, community college or university you can ask about old lab supplies or when they have surplus auctions. I've found nice lab hardware in barely used condition for cheap.

 

[Joe Camel]

There isn't a lot of temperature control with hot plate stirrers unless you get a real high end one. The heat range on mine is 100C - 600C, so I have to goose the starter on setting #1 for about 5 min, then wrap a towel around it. That keeps the starter at 25C for a couple hours.

For real temp control, you have to look for one of these

Cheers

 

[Anthony_Lopez]

I'm actually planning on building a heat controlled stir plate for my next project. I'll let you know how it goes!

 

[sigmund]

Corning makes a great stir plate.

 

[steelerguy]

Just out of curiosity, have you tried to use a magnet as a stir bar? When I made my stir plate I used one magnet on the fan and the other as the stir bar (put it into some vinyl tubing and sealed it) and it is able to spin a starter in my 1 gallon glass jug without an issue.

 

[hayabusa]

A great alternative to computer fans is a 12vDC hobby motor - They are stronger and more resilant that the computer fans.....

 

[mmb]

Just out of curiosity, have you tried to use a magnet as a stir bar? When I made my stir plate I used one magnet on the fan and the other as the stir bar (put it into some vinyl tubing and sealed it) and it is able to spin a starter in my 1 gallon glass jug without an issue.

The only concern would be sterilizing the magnet and any sort of toxins it may leach into solution.

 

[PseudoChef]

We get our stirplates from a mega-retailer like Fischer-Scientific or VWR. We have a couple different brands from Corning to Dialystir. They're pricey.

For my own use, I took one that had been sitting defunct in a cold room for 2 years. It has no spin control so it's either off or on the 10 setting...takes a lot of fiddling to get the bar to not jump when you turn it on. They let me take it free, so I'll deal with it.

I know we have a surplus lot somewhere on campus, but I've never personally been. I don't know if it's just for broken equipment or not, though.

 

[steelerguy]

The only concern would be sterilizing the magnet and any sort of toxins it may leach into solution.

Not at all, the vinyl tubing I put it in is food safe. I just sterilize it with the jug before making the starter.

 

[BrewBeemer]

A great alternative to computer fans is a 12vDC hobby motor - They are stronger and more resilant that the computer fans.....

Darn right I had a specially wired 12 volt DC motor made for me to turn over my motor, it's a 520 cubic/inch FE.

I've been working with a 1/25 hp 90 volt DC motor w/ speed controller, works from 0-1,200 rpm's that's plenty strong. So far the low speed control has a sensitive narrow range from too slow to slinging off the magnet. Needs more thinking and work.

 

[flyangler18]

If you have any ties to your local school system, community college or university you can ask about old lab supplies or when they have surplus auctions. I've found nice lab hardware in barely used condition for cheap.

My wife teaches, so I might have an 'in' with her district. I'll have her ask around.