Alexís Yeast Proofing Machine

I know very little about the science of yeast, I also know that Iím pitching in the anaerobic period. However, my method has given me great beer.


You can put Kimax or Pyrex glass directly on the stove (or I do) and from there, directly in an ice bath Kimax is an amazing glass very very low thermal expansion. I use about 750 milliliters of fresh water to start.


I then add 4 oz. of DME


You must be very careful; Erlenmeyer flasks boil over VERY quickly.



Check the internet for plastic encapsulated magnets. This picture shows three in the bottom of the flask.


After boiling, cork the wort and place in an ice bath


After the wort has cooled shake well for 30 seconds. (I know, thatís a lot)

I believe people tend to over-oxygenate there starter, I really donít think you need an air pump or any other bacteria inserting device. Just a good shake should give you all the Oxygen you need. Furthermore, I opted for a very slow agitation, just enough to release the CO2, thatís it.



The machine itís self I made from aluminum stock. Put the stock in the oven on 350 over night and let it air cool, it will be very annealed and easily bendable. Aside from a couple of magic A^2+B^2=C^2, it was pretty straight forward to design.


I just used a vise to bend the aluminum and then pop-riveted the pieces together. I cut all the marked pieces with a jig-saw and a block of wood. (I know, wrong tool)


The top plate, the floor for the flask, is a piece of particle board from a clip-board.



The gear motor was given to me at a ham fest in a free parts bin. It needed to be rebuilt, but you just cannot beat free.


From the motor, a coat hanger is supporting a magnet off of a bicycle speedometer (the magnet that is attached to the spokes)


Motor enters from the bottom of above pic, connecting with closest gear to camera, this in turn connects to the farthest gear from the camera, over to the left, and back to the right for the output shaft. The natural direction of the motor is counter-clockwise, for an end result of much geared down counter-clockwise rotation.





I used Miltec-1 on the outside parts, the gears were Micarta and Miltec is chlorinated so I used Break Free CLP on the oiling spots and Toilz synthetic grease on the gears.


I have proofed dry and wet yeast in the same way and gotten great results both ways also. I have even waited three days to pitch and have had a super fast inoculation.



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