I recently started acquiring everything I need to be able to slant and propagate yeast. I’ve never used liquid yeast before, so the first order of business was building a stirplate to be able to step up slants and make starters.
Let’s start with the speed controller
I followed the instructions from here to arrange the components on the protoboard. In retrospect I should probably have gone with a PWM speed controller in order to have greater flexibility with setting the speed. Maybe next time.
As for assembling everything in a project box, a picture is worth a thousand words:
The main concern with assembling everything is centering the magnet(s) on the fan. What I did was get some silly putty, put on the fan hub and fastened the magnet with that. Then turn the fan on (on low speed) and check for vibrations. Repeat until vibrations are virtually gone. When the magnet is properly centered, turn on the fan and mark the center of gravity on the magnet with a pen, like so:
Then just remove the silly putty and fasten the magnet with epoxy or other strong glue.
This is my finished stirplate, ready for making starters:
I have a 1000ml Erlenmeyer flask in the video, but it works equally well for 500ml and 2000ml flaks. The stirbar I got is 1 3/8″ long and teflon coated. I got it from austin homebrew supply.
I hope this post proves helpful for someone trying to make his/her own stirplate.
Before I’ll be able to make yeast slants I have a few more things I need: