Yeast Harvest/Re-Use

[oljimmy]

Searched around, could find any definite answers to this question. I've just finished fermenting a couple of 1gal WLP 775 and Notty test batches of cider, took about 15 days for each to get down to 1.001 and 1.004 respectively. I racked the fermented cider into secondary and am now cold crashing.

However, instead of throwing away the sediment, I added a bit of sterile water, swished the two mixtures around a lot, and funneled them into some 2oz sanitized glass 'Boston Round' bottles. I labeled them and am thinking of re-using them.

Has anyone ever tried this? I added two test bottles to two 1/2gal jugs of throwaway apple juice from whole foods, and sure enough within 24 hours the test jugs were fermenting away. However, I'm nervous about using these harvested vials on a larger, more expensive batch of fresh juice. Thoughts?

 

[Pickled_Pepper]

As long as your initial batches were healthy with good strong 'ferments'. I'd say you are good to use them. I've dumped juice onto a yeast cake with good results. (but I don't know if I'd use it twice) I've washed beer yeast before but never tried washing cider yeast.

If you are in doubt, Nottingham isn't overly expensive. For peace of mind just use a fresh pack.

 

[oljimmy]

Hi pepper, yeah, I was thinking of only re-using once, and only with successful batches. I figure that in the worst-case, 75% of the material in th vials will end up as sediment, so even if I pitch one and it totally fails, I just have to pitch a new packet and end up with a slightly fatter lees.

Anyway, I think everyone should be doing this. I started with just a packet each of 775 and notty, now I have 4 of each for the future with minimal cost.

 

[mopar318]

I have heard not to reuse because the yeast strain can mutate and cause problems.

Unless you can look at the strain under a microscope maybe it is not a good idea.

 

[oljimmy]

Hi mopar, that's a good point. But mutation happens only when yeast reproduce. This process, on the other hand, inhibits reproduction: the yeast are stored in a liquid that has little to no sugar, in the fridge at 36F or so, and so the odds of mass reproduction are extremely slim. In other words, the very same dormant cells that finish up your first batch can start up your 2nd one (though repeated use could risk mutation for sure). That's the idea, anyway.

 

[Pickled_Pepper]

I wash yeast from beer batches to use in a second batch all the time. It just seems my beer yeast don't have to work as hard. With a fruit must, they are out of control in "party mode" with all the sugars in there, so I haven't bothered with re-using it.

I have 4 pints of washed notty in the kegerator right now waiting to be made into starters for up coming brews.

 

[EpicCider]

I think washing yeast is great idea, but I wouldn't take the strain more than 2-3 batches because of mutation.

A lot of the yeast I previously used were so cheap, this wasn't worth the time.

However, recently some of my yeasts have been pretty expensive.

 

[Pommeau]

Just did this do to accidental dumping of few gallons of my remaining (Norman style) cider. The yeast was White Labs WLP 072, a seasonal release, so I could no longer get a fresh vial. So I just kept the ferment going after warming up a chilled "reference" bottle from the fridge to make a starter. I'd agree, not ideal, and wouldnt try to keep propagating, but it will work just fine.
I make reference bottles to compare different years/varieties I make.