Bare Bones Stirplate

[dantodd]

How long do you leave it on the stir plate? Should you oxiginate it?

24 hours should allow the yeast to consume just about all the sugar in reproduction. Assuming you are pitching a tube/smack pack into 1-2 liters or 1.040 wort.

The whole point of the stirplate is oxygenate the wort and keep the yeast in suspension. Keeping the wort oxygenated is critical because when there is O2 available the yeast will reproduce, once the O2 is consumed the yeast will begin creating alcohol.

 

[Trodd]

Ok, I got my fan, and I snagged 2 old model train controllers which has speed control and direction control. (an old Tyco model). The only issue is that the fan is 12VDC (I think, all computer fans are 12VDC) and the output on teh controller is 18VDC and 16VDC. I'm a ME not a EE, so does anyone out there know what I need to drop the voltage down to 12VEC? Is it a simple resistor or should I just get a 12VDC supply from a model shop?

 

[Seabee John]

Ok, I got my fan, and I snagged 2 old model train controllers which has speed control and direction control. (an old Tyco model). The only issue is that the fan is 12VDC (I think, all computer fans are 12VDC) and the output on teh controller is 18VDC and 16VDC. I'm a ME not a EE, so does anyone out there know what I need to drop the voltage down to 12VEC? Is it a simple resistor or should I just get a 12VDC supply from a model shop?

Ok, here's the cool part. since it's a rheostat, you should be able to hook it up to either. zero on the control means zero voltage. move it up, and so goes the voltage. Now here's the tricky part. Hooking it (your fan) up to an 18 volt controller may fry (probably not) your fan motor. It most certainly will throw your stir bar. I've got a 6 Volt DC controller hooked up to a 12 volt fan and I get to about 25% and I toss the stir bar. Some of the other folks with vastly larger brains than I have may be able to direct you down better more productive paths than I on the disparity of voltages.
good luck!

 

[Seabee John]

Check this out...second build of the bare bones...Made it for Nicksteck for Christmas.

[YOUTUBE]lDoKh0-P5yQ&rel=1[/YOUTUBE]

 

[Seabee John]

I built another bare bones stir plate. This one is a double barrel 2000 ml bohemouth. I was using 500 ml starters which worked well, but I wanted to improve two things: 1. I wanted to be able to boil in the flask 2. I wanted to reduce the "tinking" noise I was getting from the jars I was using before. I went to midwest and ended up buying the 1000 ml flasks. So here's my question... what's the largest starter per 5 gal batch that you would pitch? I figured I'd pitch into two batches (1000 ml per batch) but would it hurt to pitch 2000 ml for a 5 gal batch? let me know what you think...

here's the photo:

Bare Bones 3.1

side note: if you power two fans with one power source, make sure you buy two of the same fan. the one on the left is actually stirring... but at a much slower rate.

 

[eddie]

I made a one gallon starter using your initial design and it worked like a champ. Great idea Seabee.

 

[OCB tilly]

so...why the stirplate?

 

[Seabee John]

so...why the stirplate?

For those of us out there that like to make a yeast starter, (there are a few different reasons for this - a simple search will get you a wealth of information) you start out with a small amount of yeast, and pitch it into a "mini brew" of DME, water, and a nutrient - I like Go-Firm myself. Anyway, once you have your starter pitched, you want the yeast to ferment (grow) as much as possible. A stir plate aids this process by a. keeping the yeast suspended in the wort & b. oxygenating the yeast continually.

So say by the Wednesday before a Saturday brew, I pitch a starter of 1 LTR for a 5 gal batch. 1 ltr of yeast starter will reduce the time it takes for the fermentation of your beer. If you start out with a small amount of yeast, it takes a long time for the yeast to multiply enough to properly ferment your beer.

 

[camiller]

... what's the largest starter per 5 gal batch that you would pitch? ...

For a Lager it wouldn't be uncommon to have a 2L or larger starter.

 

[Sean]

You can sometimes get very good deals on used scientific equipment.

http://www.labx.com/v2/adsearch/detail3.cfm?adnumb=344931

no bids, $25 for a used stir plate.

ed. Right here in North-by-god-Carolina!!

 

[BeerAg]

Hey Seabee, what is the doohicky in your double barrel that has the yellow switches?

 

[Seabee John]

Hey Seabee, what is the doohicky in your double barrel that has the yellow switches?

Believe it or not, like the train transformer, it's another throwback from my model railroading days. It's just a simple track switch controller. bout 3 bucks in any RR hobby store. there are just three switches on a board. I use two of them, one for each fan. works like a charm.

 

[jameswardpeterson]

what would work great for this is an old cell phone or mobile something charger or any other wall socket transformer (found on some lamps, clocks, chargers, ALOT of things) Just cut off the adapter at the end so you have bare wires. alternatively you could just rip out the power supply from the back of an old pc and just hook that straight into the fan, seeing that the fan and power supply were actually made to work together. what is also useful is a fan controller unit. they sell them pretty cheap at computer mod places, I have 2 inside my compy for slowing down fans so their not too loud. the control range you can get on them is pretty good.

 

[Mirage]

I know this thread is old, but this whole thing got me thinking. Could you use an old computer powersupply and hook it up to an controllable computer fan? Or just hook a fan up to your computer and use that? That may be a really cheap method as most everyone has a computer... Just a thought.

 

[Seabee John]

I know this thread is old, but this whole thing got me thinking. Could you use an old computer powersupply and hook it up to an controllable computer fan? Or just hook a fan up to your computer and use that? That may be a really cheap method as most everyone has a computer... Just a thought.

Sure you could use a power supply... it just transforms the voltage from ac to dc and a rheostat will control the fan speed. That speed control is the important part.

good luck

 

[bmckee56]

So I am new to all of this and have to ask the NOOB question! What are you using the stir plate for? I work in a Bio-Medical Science Building and see lots of these devices made for the "Labbies" here.

If it is something I can make use of, I know I can get one or two as surplus cause many of the labs are re-locating to another building and they have loads of stuff they are not moving.

Thanks for any info.

Salute!

 

[Seabee John]

So I am new to all of this and have to ask the NOOB question! What are you using the stir plate for? I work in a Bio-Medical Science Building and see lots of these devices made for the "Labbies" here.

If it is something I can make use of, I know I can get one or two as surplus cause many of the labs are re-locating to another building and they have loads of stuff they are not moving.

Thanks for any info.

Salute!

We use the stir plate for culturing yeast to ferment the beer. Some people need large cultures for the style and type of beer they brew, or like me, I re-use the yeast I brew with by washing it, and then storing smaller amounts for later use. If I'm going to brew on Saturday, I'll begin a starter on Wednesday or Thursday depending on how much yeast I need to pitch. The stir plate helps keep oxygen in the solution so the yeast are at the height of viability when it comes to pitching time. I also enjoy knowing that I've got the right abount of yeast to do the job... not too little, not too much.

You can figure this out by using the pitching calculator at Mr Malty Pitching Rate Calculator

good luck!

 

[bmckee56]

John: I appreciate your response to my question. I understand more now.

Salute!

 

[BrewBeemer]

Function before beauty, what's a pretty stir plate box if the unit doesn't work properly. Details can follow later if a box is needed. A lot better than throwing big money at a lab stir plate unless you got it cheap, I never could. Oh by the way that Mr. Malty Pitching Calculator is in my file and a great tool to use, thanks for posting it.

 

[Yunus]

I havent read every post here but I made a stir plate in the DIY fashion. The magnets I used were kidney shaped ones out of a Hard drive. Very powerful. I found that putting 1 magnet in the center of the fan worked but I have yet to get it working with 2 magnets. Just an FYI for anyone having trouble. Also I use a very small stir bar, about 1/2". It can make a funnel in 2l of water though.

 

[Foosinho]

I did this same thing nearly 2 years ago. Except instead of using a spare model train controller (I have one of those, actually), I used a power supply I had lying around from another project from Radio Shack that has a switchable voltage with about 5 presets. Got my rare earth magnets from RS as well.

It's "ghetto", but completely functional.

 

[Seabee John]

I havent read every post here but I made a stir plate in the DIY fashion. The magnets I used were kidney shaped ones out of a Hard drive. Very powerful. I found that putting 1 magnet in the center of the fan worked but I have yet to get it working with 2 magnets. Just an FYI for anyone having trouble. Also I use a very small stir bar, about 1/2". It can make a funnel in 2l of water though.

The trick to getting two magnets to work, is first getting the polarity of the two magnets right, the second is getting the center line of the two magnets to line up correctly with the center line of the fan..... otherwise, the stir bar will "orbit" around the center of rotation and ultimately be tossed.

so:

1. magnets must be equidistant from the center of the fan
2. magnets must have the proper polarity alignment

stir bar (- +)
mag 1 (+) (-) mag 2

3. center line of magnets must align with center line of fan.

I also found it helpful to space the magnets so the end of the stir bar was even with the center of each magnet

hope that helps

 

[Madtown1]

Great post Seabee...thanks for the all the insight. I am just about to put mine together... can't wait to fire it up. :rockin:

 

[Seabee John]

Great post Seabee...thanks for the all the insight. I am just about to put mine together... can't wait to fire it up. :rockin:

Drop A couple a pics in here so we can see what you've done!

 

[fizgig]

I tried this but apparently my fan is not powerful enough, it couldn't move the magnet, using an old school Lionel transformer and a 100mm fan, a magnet from a hard drive.

Any tips/brands to use? I already wrecked one fan.