TOP CROPPING YEAST LIFE

[Lele]

Hi everyone

How long can I use a top cropping yeast? In "Yeast" by Chris White there's written (about a top or bottom cropping yeast): “After four weeks, the yeast viability is usually 50 percent or less. Ideally, you do not want to pitch yeast that has dropped below 90 percent viability.”

But in other web sites there's il written that top cropping yeast loses 20% of his vitality every month, and so I can use a top cropping yeast until 5 or 6 month.

What's your experience?

Thanks

 

[cire]

Certainly 2 weeks has proven practical for me. Lag time is much bigger after a month, but recently pitched one after 3 months that took most of a day before producing a full covering. Also, the older the yeast, the greater proportion of dead cells pitched.

It depends upon the amount pitched which in turn depended upon how heavy a top crop that particular yeast produced. Mine is roused for 3 days, when the cap begins to subside and becomes more dense to be cropped a day or two later.

I have found adding about an equal volume of fresh wort onto saved yeast quickly gets it into action.

 

[bleme]

In "Yeast" by Chris White there's written (about a top or bottom cropping yeast): “After four weeks, the yeast viability is usually 50 percent or less. Ideally, you do not want to pitch yeast that has dropped below 90 percent viability.”

I don't think you can make a blanket statement like this about yeast when there is so much variation between strains. Just look at Garshol, bring back yeasts that have been sitting unused for over 30 years!

Also have to recognize that Chris White is CEO of White Labs and wants to SELL yeast. It may not be intentional, but when he looks at studies, he is going to agree with ones that fit his bias. He is going to 'spin' everything in a way that increases his business.

 

[cyberbackpacker]

I have been top-cropping and re-pitching WY1469 from a pack that I originally pitched at least 2.5 years ago. Attenuation is consistent, as is flavor profile.

YMMV