I have been yeast culturing or "ranching" for some time now. I find it brings me that much closer to making the beer completely from scratch. Everything was great at first and ok still. But Ive noticed smaller growths when making a starter compared to when I first started. So after talking to a few microbiologists, doing lots of research on a site called Homebrewtalk.com (the best site ever ), And listening to a few pod casts. I see no other choice but to move my master stocks into the freezer and re-culture from that to a working plate every 4-6 months. For a better vitality of the yeast master stocks I will remove as much water as I possibly can, move to the fridge for 24 hours then to the freezer. In order to do this I feel centrifugation is the only way to go. But not being able to drop a couple hundred on one I had to break out the old D.I.Y. toolbox and here's what I did.
I attached a sting to the red capped tube by drilling two holes near the top. I tried not to get too close because I didn't want to loose to much structural integrity.
The tube of yeast slurry I got from the bottom of a starter slides right into the red capped tube. Put the cap back on for support and just in case the tube breaks. Grab the end of the string and get to spinin that thing like it was one of those airplanes attached to a string. (Note: Watch out for children, pets, and SOWMBO <----her)
I spin for about 30 seconds to a minute. How long you spin really depends on how many you have to do, and how long you can last with out passing out.
After a quick spin I will pipette off the liquid part top up with more slurry and spin again until I get about 3-4 ml of compacted yeast. Add about the same amount of mineral oil and begin the freezing process.
I attached a sting to the red capped tube by drilling two holes near the top. I tried not to get too close because I didn't want to loose to much structural integrity.
The tube of yeast slurry I got from the bottom of a starter slides right into the red capped tube. Put the cap back on for support and just in case the tube breaks. Grab the end of the string and get to spinin that thing like it was one of those airplanes attached to a string. (Note: Watch out for children, pets, and SOWMBO <----her)
I spin for about 30 seconds to a minute. How long you spin really depends on how many you have to do, and how long you can last with out passing out.
After a quick spin I will pipette off the liquid part top up with more slurry and spin again until I get about 3-4 ml of compacted yeast. Add about the same amount of mineral oil and begin the freezing process.