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Yeast Preparation

Before you can begin to brew beer you need to have your ingredients. Most you can buy ahead of time and keep around til ready. Yeast, on the other hand, needs to be as fresh as possible. Another aspect of yeast is, the more beer you make and the higher the gravity (sugar content), the more yeast you need. Commercial liquid yeast can get very expensive when you need to use 3 or 4 vials per brew at $7 a vial. Another option is to make a yeast starter. This is basically a mini batch of beer that is used just to multiply your yeast count for your main batch. This does take a few days so it needs to be done ahead of time. To find out exactly how much yeast you need, head over to Jamil's Webpage and use his Mister Malty Pitching Rate Calculator.

To take it a step further, you can collect your own yeast using slants (test tubes with agar media to grow yeast). The difficulty with this is the need to keep things as sanitary as possible or you'll end up growing more than just the yeast you want. Once you have your own slants of yeast they can be grown up into any amount of yeast you would need using various size starters.

I wanted to get some sort of flow booth to keep my yeast culturing activities as clean as possible. All the ones I could find were way too big. I decided to build my own. I bought a ULPA (Ultra Low Penetration Air) filter. You can see in the picture it is the 2'x2' metal box on the top of my booth. I then got some lexan that was leftover from a jobsite. I cut and assembled all the pieces so they fit around the outside of the filter. I then sealed all the seams with silicone. The filter has about 6" of empty space in the top. This is where I installed a 20" box fan. I sealed all around the fan so the air is forced thru the filter. With this setup there is always a supply of positive pressure super clean air inside the booth. I tested this out with a plate of malt agar left exposed. After two weeks there was nothing growing on the plate. Success! The microscope helps count the yeast cells to be sure they are healthy.

You can also see in the above picture the two black boxes, they are stirplates. Yeast starters grow so much faster and better when constantly stirred. Using a stirplate and magnetic stir bar you can continuously stir your starter ensuring the best growth possible.

Now you have your yeast ready to go. Let's go to the next step.

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