Yeast Starter Frozen in Fridge - Is it bad?

[Hudini56]

Well my conan starter I have been using an saving (1500ml starters saving 500ml in mason jar, using 1litre for brew) The 500ml saved yeast semi froze in my fridge. Apparently had a malfunction with the fridge and got too cold.. Any thoughts? Will it be ok? should I warm it up, make a starter and see if it ferments?

Never had this happen to me before. Anyone experience this?

 

[IslandLizard]

If it semi froze, slushy, chances are it's going to be fine. It's the hard freeze that causes most damage, but won't kill it all.

I'd make a new overbuilt starter from the decanted slurry, and keep it going.

I keep my yeast jars all together in a cardboard box on a shelf to reduce larger temp swings.

 

[Hudini56]

It didnt hard freeze, so I guess thats good news. I will make up a starter and see what happens. Should I stick with a .040 starter or do you think I should go a little lower like a .030? Less stress?

 

[IslandLizard]

I'd say 1.037-1.040, what you usually do, is fine.

I meant to ask, when you make a 1.5 liter starter, save 500ml out for the next batch, then make another 1.5 liter starter from that, and so on, do you do that perpetually? Or start from fresh after so many cycles?

 

[Hudini56]

I use the 500ml to make a 1500ml starter, and pour off 500 to save for next starter, use the 1litre for the batch. And I have been continuing that process now for 4-5 or batches. I do not wash from the fermenter. I know I could, but I have had good success the way I have been doing it, and I tried washing once and I was not too successful.

I propogated this yeast from 2 heady topper cans in early november of 2016, so about 4 months ago. I have been using it every 6 weeks or so in a batch, but I am calling gen 4 or 5 because when I first got it from the cans, I stepped it up over the course of 4 starters, going from a .025, to a .030, .035, .040 in succession after cold crash and decant, about 2 weeks time, until I was getting a real nice ferm and healthy looking yeast cake. I brew NEIPAs with it, and I am using it in lower OG in the .055 range. Ferm usually starts within 8 hours, and mostly done in 48 - Completely finished in 4 days.

I have read that using this type of yeast from heady can usually gets the best around batch 6, and starts to fall off after 10 i think. I figured I would just have to keep using it, until I notice any off flavors or low attenuation. If that happens then I will just get some more heady and do it all over again.

 

[IslandLizard]

Sound like a good plan.
Now you're getting to your target generation 5 or 6, how about building one 1500ml starter, split 3-ways, 2 for keeps (reserves), 1 for a new starter?

The 2 you keep are of that last generation say 5 or 6. Use the last 3rd for the next 4-6 fermentations until it isn't quite up to snuff anymore, then make a starter with one of the reserves for the next 4-6 rounds. Then on the 2nd reserve. You my want to reactivate the 2nd reserve at some point along the way, so it doesn't get too old before use.

 

[Hudini56]

That's a really good idea. And since I will need to be waking it up now to see if I can save it, might be a good time to do that. I plan on brewing thursday, if I am questioning this conan I will just use a s05 or s04 for this batch.

I question how long I can keep a yeast in between uses. I was thinking really no more that 3 months, but would rather stick to about 2 months.. thought on that?

 

[IslandLizard]

6 months seems to be about the maximum, judging by most calculators' conservative estimate of having about 10% of cells left by then.

That said, I've made starters from yeast that was a year old or even older. I did the same you did as when harvesting from a commercial sample. Build it up in 2 or 3 steps with lower gravity wort.

Where I get "fresh" yeast packs of WLP or WY they tend to be 2-3 months old, often more. The one store has a huge inventory of WLP, pretty much the whole collection, including Platinum strains. They stock multiples of most, and piles of the common ones. Must be a real bear to prevent too many from expiring. I've never seen any of them on special sale there or closeout because of age. Maybe they return or get credit for those that didn't sell? Curious business dealing with relatively short lived stock all the time.

Forgot to mention, you can freeze them safely by adding some glycerin to them, following a slow freezing procedure. 2 years of storage seems to be very attainable that way, with fairly high survival rate.

 

[Calder]

I don't count starters as 'generations'. Starters are lower in alcohol, lots more oxygen, and very little head pressure. Conditions are a lot ess stressful than a full brew.

Yes, it will eventually mutate, but I think you can go a lot more uses if you only use starters.

I make starters, and save some for future use, but make several beers by re-pitching part of the trub. I use a number of yeasts, so may not need the yeast again for a while. I have had no problem getting yeast starters going from 2+ year saved yeast from starters.

 

[Hudini56]

I use the generations counting for my own use, I understand its not "pc" in the brewing community, but works for me..

Yes I kind of thought using the yeast from starters over and over would get me a lot further - so I guess I will use it for as long as it lasts.

2 years? Frozen or just put away in the fridge?

 

[Hudini56]

To add to my comedy of errors, I took my mason jar out, put it in a pot of warm water and set the stove to low. I've done this many times before just to warm up my starter yeast to room temp. Well well, I walked away to send an email, 10 min later I come back, to see I didn't in fact set the stove to low, and it was roughly medium heat, wort in the jar was 114 deg.. stupid stupid mistake there.. just going to to my starter and see where I end up.. time to screw my head back on straight I guess

 

[Hudini56]

A quick update.. took longer than normal for my starters, but I have a good ferm going on now at 24hrs. Solid activity, so I didn't kill it after all. Hopefully I didn't damage it either. Will be pitching it into a .065 on Saturday