Thursday, March 31, 2016

Just a stirrer

In my quest to make the perfect beer I put together a home-made plate stirrer last night. Essentially it's a device for stirring liquids (unattended) and the reason for having one in the brew process is to help get yeast fighting fit and able to do the best job it can at fermenting your beer. What you do is 24 hours before brew day you take some yeast and mix it with some water and malt extract (essentially sugar), then you put somewhere warm and stir it continuously (hence the need for a stir plate) After 24 hours the yeast cells should have multiplied in number and started fully working ready to be dropped into the wort (un-fermented beer) where they will hit the road running and get busy converting all those sugars.

I wanted to make this little device on the cheap so I got an empty plastic box, a fan from an old PC and a strong rare-earth metal magnet from an old hard-drive and wired up the gadget you can see in the video. For ease of use I added a switch and a potentiometer (to adjust the speed of the fan) and then glued the magnet onto the fan casing. When switched on the fan rotates the magnet and all I needed to do was place the jar with the yeast in it on top of the box along with a magnetic bead which then rotates with the magnet attached to the fan (via magnetic attraction). Hey presto a plate stirrer for about a fiver (it normally costs around £75-200 to buy a commercial/professional unit)

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