Frozen Starter

Yeast & Fermentation
1

Well I think I screwed the pooch good on this one, so I’d figure I would share my experience.

This weekend I brewed an experimental batch with S. eubayanus and, despite the frigid temps, the brewing process went pretty well.

I wanted to do a Köstritzer clone with this yeast. All worked well, I mashed pretty low 147 for 90 mins, 90 boil, ultra quick chill. Now I go to my chest freezer where I was storing this monster 4L starter, and noticed that I unpulgged my JC A419 to replace it with my new Fermestat. and plugged in just the freezer with no temp control. Well, long story short, my starter was a block of ice when I went to retrieve to pitch it!

I went into full panic mode and got the starter in cold water as I contemplated what to do. I knew I didn’t have anymore access to this strain and didn’t want to wait a day to get a different strain. I was also worried about leaving the wort alone to get infected.

So I decided that I was going to try and save the yeast. Not a good chance, but worth a shot.
I got the starter back to room temp- by about midnight- Sunday evening, and pitched another 1L of fresh wort (made a DME starter) on top of it and put it back on the stir plate and went to bed.

I figured it was all but dead, but when I woke up yesterday, I noticed some krausen in the flask!!! I let it go for about 12 hours and then I got it back in the fridge to settle out overnight.

I woke up this morning and noticed it did not barely settle, Maybe due to it was 5L of wort, or the cells exploded and there was noting to settle. Who knows?

So I pitched the entire thing. Oxidized wort and all.

Now this experimentation to see what S. eubanyanus would taste like in a Schwarzbier has turned into an experiment of “did anything survive?”

My expectations were low going into the original experiment as, from what I understand, not too many have had much success with this strain, in optimal conditions, let alone the extremes that I put it through.

I want to RDWHAHB, so if anybody has a similar experience (frozen starter) that worked, please chime in.

On the good end, I learned that I can brew in -2 weather.
Bad thing is I may have done it for no particular good reason.

2

Day 2: High Krausen

Acetobactor?

No vinegar smell coming from the air lock.

Stay tuned…

3

I guess I am the only one that botched a starter? :shock:

4

Haven’t botched a starter in that way, but I did botch a start-up this past weekend. Forgot to change the temp controller on my fermenting fridge. I kegged a batch of lager I’d been cold crashing earlier in the day, then put my IPA in there to ferment. The ale yeast didn’t like the 38 degree temp that much. They were much happier when I realized my mistake the next morning.

5

Hi Pkrone:

Did the IPA wort get down to 38 degrees? And I assume that the fermentation is going well?

I have never made this kind of mistake, so I am interested in how the brew turns out. By the looks of things it is fermenting away nicely. I do not smell anything that would hint infection, but it’s early yet.

At this juncture, my main concern is adding 5L of oxidized wort to my batch. In the name of science I am concerned, yet I am intrigued.

disclaimer to all

I will try and periodically bump this thread, so I do not forget to post the results.

6

The thermometer in the fridge read 48 when I checked on it the next morning. That’s probably a good reflection of the temp of the wort. I just opened the door and let it come up to room temp. I was amazed at how fast the krausen started to form as the wort warmed up. I guess the yeast were just itching to get going.

7

If what you have looks like a regular krausen then I would leave it. I think it’s OK. I’m not sure about frozen yeast. I don’t think you killed it though.

Acetobacter has quite a different look from pictures I have seen.

8

Well I moved this disaster to a lagering vessel (corny keg yesterday). I hit my gravity targets. Starting 1.048 finishing 1.017; which is about where I thought this yeast would end up. Not too bad, but there is a huge problem. I smelled what I detect is Hydrogen Sulfide. The first whiff is pure @$$. I am hoping to lager it out, but I am not too sure that is possible.
Also, there is a strange taste, it’s not aggressive or overly funky, rather this is a slight fruity tingle on the tongue. Kind of like a weak Alka Seltzer sensation if mixed with Koolaid. It’s really hard to describe.

Has anyone had issues H2S in a lager? If so, were you able to remedy it by lagering for a long cold period, or is this beer basically what it is and it might be better served watering the garden?

What I do know is that I probably will forego any future opportunity to ferment with S. eubanyanus.

9

One of the lager yeasts I use wy2206 I think, produces a sulfur odor during fermentation. I notice it most when I raised temp to 60s for a d rest. It may just be a natural byproduct of the yeast. I’d let it ride. Could be you’re just searching out flaws.

10

Thanks Danny! That is a good point because the beer was at about 60 degrees when I noticed it. The taste isn’t that bad, so I’d hate to dump it over the farty smell. :cheers:

11

Lager yeast are notorious for the sulfur carry smell. It should age out. Before I had my temp controlled Conicals I would use my lager chest, a chest freezer as my fermenting chamber. I would brew 10 gal batches in 2 carboys. I would open that lid… talk about nasty…

12

Thanks Loopie that puts my mind at ease. I have worked with several lager strains, but this takes the icing on the cake for the funk level.

13
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14

Well this beer was unique to say the least. It kicked off a huge amount of H2S and smelled like a sewage treatment plant. I lagered for roughly six weeks at 35 degrees and couldn’t get it to clear. It was cloudy and just outright funky.

I suspect some sort of gram negative infection (given the environment that it was brewed and fermented in), but I cannot pinpoint it (maybe Pectinatus due to the high sulfur taste and overall bitterness of the beer; i.e., think the tingle you get after eating a raw lemon).

I tasted some of the batch at various points, offered some to the brave, but ultimately dumped it down the toilet. The consensuses was that it was “funky, and not fit for human consumption”, so it had to go.

Sad day and sadder experiment. In the end, I will never attempt to brew with S. eubanyanus again.

I mean, I have made some clunkers in the past, but never so bad that I thought I may get someone sick from drinking it and eventually dumping it.

15

Sorry to hear that this went bad. I don’t think you can really judge the yeast by that experience though. If everything went right and that was the final product then yes, the yeast sucks. But with that, not exactly the best rendition.

16

“I don’t think you can really judge the yeast by that experience though.” This is very true. Hopefully soon enough there will be more data on this strain and how to handle it and what to expect from it. I guess my fatal flaw was letting the starter freeze and then having unpitched wart sit for two days. I suspect the later of the two is the source of my infection.

If this strain does become commercially available, I will experiment with it again (providing there is a little more data on it).