Yeast harvested from blow off, or bottom of conical

[Jtvann]

Which would you choose as better to harvest. Yeast from blow off, or yeast from a conical dump?

 

[couchsending]

Depends on the yeast...

If you have a top cropping strain then top cropping will generally always provide you with 100% viable yeast. If it’s not a top cropping strain you’ll have to harvest from the bottom and again depending on a few variables you may end up with less viable yeast, but maybe not.

 

[madscientist451]

I know that top cropping is the recommended method, but I've been re-pitching yeast slurry from the bottom of the fermenter for years without any problems.

 

[Jtvann]

I had setup what I thought was a pretty cool idea to test out both options. I have a Ss unitank. I attached jaybird yeast harvester to the triclamp blow off cane, with the CO2 hook up going into a sanitized jar. I figured CO2 would blow on out, collecting any yeast blown out.

Well apparently Wlp004 is a monster. In less than 24 hours my 32oz harvester jar was full, and liquid was to the brim of my 1L blow off flask. In theory it would have worked, but this attempt is a no go.

Were gonna need a bigger boat

 

[Robert65]

There really aren't many true top cropping strains left in the world. Through the 20th century even traditional British brewers moved from the old systems to modern conicals, and so their yeasts have been selected for bottom cropping. In fact the shift began long before that, by the turn of the 20th century, when aged stock ales fell out of favor and were generally replaced by what we know as cask ales; this required selection for bottom fermenting behavior so the yeasts would pack down quickly in cask. So it is a good bet that most ale yeasts today are suitable for bottom cropping. Kind of the default position, unless you can determine that a particular yeast is actually suitable for top cropping.

A side by side comparison of the performance over multiple generations of a given strain harvested by each method would be very interesting.