Propagating Top-cropped yeast

[BrewMasterBrad]

I am trying a new way of propagating my yeast. In the past, when I wanted to re-pitch yeast, I would simply pour the yeast from a previous batch into the next batch. No thought about washing the yeast or pitching rates. Lately I have been rinsing the trub out of my yeast and trying to pitch the right amount of clean yeast into every batch of beer. Last month, I tried top-cropping some WLP001 off a batch of Blonde Ale. To do this I boiled some filtered water in a 1L flask and let it cool. I took a long stainless steel spoon and sanitized it. I skimmed some of the yeast off the top of the fermenting Blonde Ale and put it in the flask. I ended up with a light dusting of yeast at the bottom of the flask. After I let the yeast compact at the bottom of the flask, I decanted the water off the top and added 1 quart of my canned starter wort and put it on the stir plate. The worked great and I ended up with about 30-50ml of pure yeast at the bottom of the flask. I needed to grow some more yeast from this in order to try it out in a 10 gallon batch of Blonde Ale. I decanted the liquid off the top and add the yeast to 3 quarts of starter wort in my 4L flask. It took off almost immediately and in the morning the picture below shows what I have going right now. Usually the swirling action of the stir plate keeps foaming down, but this sucker is crazy. I will take another pic when it is finished so you can see how much yeast was produced. I am planning on brewing on Thursday with this pitch of yeast and I will definitely be using a blow off tube!

[brahn]

That's really cool Brad. I've thought about trying to top-crop, but I've never tried it myself.

[JonGoku]

I don't think you ever chimed in on the Fermcap-S thread I started, but perhaps if you haven't used it before this might be a good chance to try.

[BrewMasterBrad]

I don't think you ever chimed in on the Fermcap-S thread I started, but perhaps if you haven't used it before this might be a good chance to try.

I prefer not to use it. I have tried it in the past, but I just don't like putting anything foreign in my beer. I'm the one that voted for option three on the poll in that thread.