Deadline to harvest?

Would there be any problems harvesting yeast after 4 weeks primary? I typically transfer to secondary after two weeks and harvest then but Ive got a few half batches going that I don’t wanna bother transferring. Is there any benefit for doing it soon rather than later? Does it matter?

From yesterday:



Your going to lose viability faster at room temperature than if you had harvested and stored in the fridge.

I’ve run some experiments on this. There isn’t much of a drop in viability from refrigerator or ambient storage. What will kill yeast is ambient storage when the alcohol level is high. If your ABV is less than 7% you should have 40% or better viability after four weeks at ambient.

Keep in mind this is just viability. Vitality is another question.

Post on ABV effects on yeast stored at ambient is coming 1/26

viability effects when refrigerated: ... ility.html

viability effects when kept at ambient: ... bient.html

Care to share your testing method?
Just curious which staining method you are using since methylene blue has known inaccuracies.