Thoughts on What To Do With Aging Hansen Ale Yeast

[smata67]

So back around June (9 months ago), I received the Hansen Ale vial to the far left. The batch had definitely experienced some summer heat stress, but I made a 1.5L starter with 1/2 of the vial, split that starter, pitching half into a 5G batch and saving the other half. That is the middle short jar. That yeast is also about 9 months old. The starter was very "cidery," but I used it anyway. It made a great black IPA, but I felt it was left a tad underattenuated at 1.019. I had to take measures to get it to down to 1.019, in fact. I concluded that I most likely underpitched that batch due to the heat stress and dividing the starter. Good beer, though, no complaints. This was in October. I saved that yeast from the black IPA and pitched it into an IPA in November (5 months ago) that came out great, best IPA I have brewed to date. It attenuated to 1.009 with an ABV of about 7.3%. That is the larger jar which includes some of the trub from that batch. I want to remake that beer.

The yeast in all three jars looks great, I am fairly consistent with my sanitation, particularly when it comes to yeast. All jars were refrigerated with loose tops. The original vial smells as it did when it came in, the starter smells cidery like it did 9 months ago, and the latest batch which is a second generation yeast looks and smells healthy. So clearly, the obvious approach is to use the latest yeast which performed very well and appears very healthy. But I have some original yeast (remember, this produced a cidery starter) and its first starter and I'm having a hard time with the idea of just tossing it at this point. You could say I've somewhat grown attached to the critters. They are, after all, the purest strain I have, though probably a high mortality rate there. Anyway, thought I'd float out my situation and get some thoughts on what to do. For now, I'm planning on combining the first two jars and making a starter to see what happens and getting a starter going with the larger jar for pitching into my next beer.

 

[Dr_Jeff]

My advice, for what its worth, is to use the latest yeast and do a starter from that to brew with. (known good)

Take the original batch, decant most of the old beer, do a new starter with it and evaluate the finished starter, if it smells normal, step it up a time or two, so that you have more of it and continue to propagate it and brew from it as the time comes.

Possibly share some of it with your local brewing friends.

 

[bkboiler]

edit - deleted a bad joke about MMBop.

 

[day_trippr]

Given this is a blend of who knows how many strains I wonder if it's worth salvaging any of that given one would not know what the fatality rates and propagation rates of the various strains might be.

Whatever comes out of a "Frankenyeast" starter might have little resemblance to its predecessor...

Cheers! (Which, I suppose, almost mandates doing it, just for SCIENCE! )

 

[smata67]

Results are in! The recovered yeast from a batch brewed 9/19, the larger jar, was dropped into a 1L starter then pitched into a 5G batch and that fermentation took off like gangbusters, full krausen in less than 12 hours and still ocassionally bubbling 4 days later. So at 6 months, a very good survival rate, though this was originally a fairly large population, maybe 400B? Six months is about my limit for storing previously pitched yeast, this probably would have been fine for a few more months. If everything goes well, should have a dry beer < 1.010 like the previous batch.

The vial, manufactured in 6/19 (so 9 months old) with an expiration of 9/19, was all dead. No change in OG in the starter after 24 hours. I then pitched half of a starter made in 6/19 and that slowly fermented out over two days. Took FG down to 1.010 for a 74% attenuation. Cidery odors, much like the first time back in 6/19, though that has largely dissipated. I estimate an 80B population now, may very well do another 1L starter and pitch into a 2G batch for kicks.