Yeast recycling

[cookmysock]

Did my first yeast re-use yesterday.

Took a very simple approach. When I finished bottling from the primary, I simply poured the yeast, etc in the bottom of the fermenter into a sterilised plastic juice bottle. Straight to the fridge. Probably had about one litre of yeast, trub, etc

Next day, made a Maris Otter / fuggles smash brew. Used about 2 cups of the wort and thoroughly mixed into the bottled yeast and left at room temperature (14 deg C - cold here in Sydney at the moment..) for 3 hours

Pitched the full amount of recovered yeast at about 23 deg C

Within one hour the fermenter was going mad. I have never seen such a quick start to fermentation and the airlock was lucky to have any water left in it! A huge amount of krausen as well.

I used a Wyeast 1728 Scottish Ale by the way.

The reesults have been effective so far. Is this an okay way to re-use yeast? How many brews will I get out of it? I usually brew 14 litres per batch

 

[HopLife]

If you have good sanitation you can essentially use the same strain of yeast inevitably. In practice most brewers replace their yeast every few brews. I have gone as many as 7 or eight brews before I lost confidence in the health and sanitation of my yeast.

 

[tre9er]

Perfectly acceptable. Re-using it that quickly after you harvested it means you don't even need to make a starter. If it was a week or two later, I would then make a starter.

Tip: You can take that yeast cake from the fermenter, pour it into a large container, shake, then wait 20 minutes...pour off just the top-most liquid and split it into 4 containers. Each one represents enough yeast for a batch, generally.

 

[jimdeasy]

I’ve been wondering about taking yeast from a blow off tube bucket. I get a big yeast cake at the bottom of my blow off tube bucket and it looks clean! Is this technically “top cropping” the best type of yeast harvesting?

 

[odie]

I have roughly a pint remaining in my bucket after I keg. It's basically pure yeast cake since I strained the wort before fermentation. I'll stir it up good since it's packed tight. I can fill two 1/2 pints to pitch the next time. Only need one and the other is a back up. Keeps for months.

 

[FromZwolle]

I’ve been wondering about taking yeast from a blow off tube bucket. I get a big yeast cake at the bottom of my blow off tube bucket and it looks clean! Is this technically “top cropping” the best type of yeast harvesting?

close enough, but i wouldn't use this since it's sitting in an open container exposed to whatever yeasts, molds, and bacteria in the air.

 

[bobeer]

This is basically how I've been reusing yeast for years. I used to go to the trouble of washing the yeast but I found it doesn't matter as long as its relatively fresh yeast. I've used yeast that I've had in the fridge for a year that eventually woke up on my stir plate but I try to reuse within a month or so or I'll just buy fresh yeast.
I'll also dump yeast that has ripped through a high gravity wort.

 

[mashpaddled]

Yeast is not so expensive that you should risk infected batches repitching questionable yeast but there are also several good reasons to repitch yeast, too. For the past like six or seven years I've severely reduced the amount of repitching from batch to batch in favor of maintaining mother cultures that I feed and replenish periodically and harvest from to grow starters. This ensures a healthy yeast that is more true to the original pitch than successively pitching from batch to batch. My infection risk is far less and similarly very little risk that my cropping method is affecting the attributes of the cells harvested. I keep mason jars of yeast on fermented wort. When I need yeast I drain off some of the beer on top, pour off some slurry into a flask and feed both with starter wort. After the mason jar ferments for a few days the lid is tightened and it goes back into the fridge until needed again.