For those who are interested in making yeast starters

[Steve973]

The very best way to make a starter is with a stir plate that provides both continuous agitation and continuous aeration. Normally these things run up into the hundred dollar range, but a friend of mine put me on to a much more affordable solution:

http://www.stirplates.com/stirplate.htm

If you don't already know, a stir plate will nearly double the number of cells that you can create in a starter, so where you might normally need a two liter starter, a one liter starter would suffice.

Note that you need a special filter in your one-hole stopper so that you don't pull contaminants into the starter.

 

[Nova]

Good idea that, i may try and make one sometime with rare earth magnets and a computer fan.

 

[TXCG]

Eh, its not too bad of a price I guess, but you do realize that circuit is copied exactly from the LM317 datasheet, right? It's just set up as adjustable voltage regulator using the potentiometer to control the set point. You could pick up everything to make that off of digikey.com or mouser.com (or, ew, radio shack). And no sense in using a PCB for something that simple, just get a tiny piece of breadboard.

http://www.national.com/mpf/LM/LM317.html

 

[Steve973]

Yeah, that guy is helpful and provides all of the info for those who want to build it themselves. However, it's not a bad price, compared to other commercial sites that offer the product, if you don't want to build it. There are plenty of brewers, I'm sure, who have never picked up a soldering iron.

 

[imaguitargod]

Eh, you don't need all that. All you need is just a pot, computer fan, rare earth magnet, and a 9 volt batery attachment and you're done. It'll cost you all of $5 if that...

 

[Steve973]

The only potential problem that I see with your solution is speed. You don't need a whirlpool that extends to the bottom of your flask. What happens if you're spinning too fast?

 

[TXCG]

The only potential problem that I see with your solution is speed. You don't need a whirlpool that extends to the bottom of your flask. What happens if you're spinning too fast?

That's what the potentiometer is for. Using the pot without the regulator is a less efficient way of doing it, but I don't see any reason why it wouldn't work.

 

[imaguitargod]

The only potential problem that I see with your solution is speed. You don't need a whirlpool that extends to the bottom of your flask. What happens if you're spinning too fast?

That's what the potentiometer is for. Using the pot without the regulator is a less efficient way of doing it, but I don't see any reason why it wouldn't work.

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What he said

 

[Steve973]

Missed the part about the pot.

 

[dreamboat]

I do things a little differently with an aquarium sized air pump, drawing through a filter, and pumping for short periods of time at regular intervals - keeps things suspended and fed with a good supply of oxygen. i will have to track down a picture sometime.


dreamboat