My simple yeast propogation technique

Just wanted some feedback on my method for propogating yeast, if it's helpful or if any problems are forseen.

Here's what I do - basically eliminate harvesting from the carboy

1. Start with vial of liquid yeast
2. Boil 1/2 cup of light extract in about 4-5 cups water for 20 mins
3. Let it cool to room temp
4. Pour off the liquid into sanitized 2 liter soda bottle (leave as much of the trub in the pot as possible).
5. Fit with small stopper and airlock for 24-48 hours
6. Shake up the mixture and pour off enough to fill 1 sterilized small mason jar. This is the yeast for my next batch.
7. Boil another 1/2 cup light extract in 5 cups water, cool, and add to the remaining starter.
8. Decant and pitch to next batch of beer after 24 - 48 hours.

Rinse and repeat, only now for step 1 just use your stored mason jar from the prior starter.

I have kept the mason jars in the fridge for over a month with no ill effects.

I think this method reduces the risk of contaminating the yeast since you never harvest from the carboy. I also dont bother washing the yeast, I just decant the spent wort off it and add a little of the new wort when i shake it up to resuspend the yeast.

Comments?

There are many ways to skin that cat. Yours is one of them. Nothing wrong with what you're doing. You could stretch that out a lot more though with minimal effort beyond what you're already doing.

Loved your write-up on never ending Liquid Yeast. I didn't mention that I yeast banked off my initial vial. I like your idea of doing it in bulk, I just used a small yeast bank kit from my local homebrew supplier. I will probably get 50 batches off my first attempt, but maybe more if I can keep going without getting odd flavors. Thanks for the great post.

This is what I do, seems to work great. I have a "library" of 10 or so yeasts now. No trouble yet, but I imagine being as close to sterile as possible is of utmost importance.