is my yeast dead?

[Zwerg]

Making a pseudo-märzen using WY1007. When I got to the store, I found only one smack pack left, and it was 4-5 months old.

I never made starters before now, but I just bought a stir plate and 2L flask, so I figured I could try to revive the yeast. Pitched the yeast into a 1L starter about 18 hours ago and put it on the stir plate. Unfortunately I was a little impatient and didn't carefully check the temperature when I pitched it, and I think it may have been around 80 F - I realized this a few minutes after I pitched it and put the flask in a water bath, so it cooled down further pretty quickly. Then I put it back on the stir plate and left it over night.

It's now about 20 hours later, and turning off the stir plate and letting it rest for about an hour I haven't observed any change. There's no yeast or any other sediment at the bottom of the flask. No activity visible in the wort. It's somewhat cloudy, but it was cloudy as soon as I pitched the smack pack and doesn't look different now as far as I can tell. Photos were taken just now, after sitting on the plate overnight.

Should I give this more time? Maybe if viability was extremely low it just needs more time to activate?

 

[Jaybird]

It may be lagging. Pitching at 80* although not ideal wont kill that yeast. just being a little older can make it a slow starter but it should still eat. I personally would give it another 24 and then check your gravity if you are not seeing any visible signs. Keep in mind on a plate you wont always see it ferment.

Cheers
Jay

 

[Zwerg]

Thanks! Okay, I'll give it some more time. Do you think I should keep it spinning for another day, or just let it stand? I've heard spinning for too long can stress/damage the yeast, but I've had it in a pretty slow speed, just enough to get a noticeable whirlpool/dimple.

 

[Jaybird]

Thanks! Okay, I'll give it some more time. Do you think I should keep it spinning for another day, or just let it stand? I've heard spinning for too long can stress/damage the yeast, but I've had it in a pretty slow speed, just enough to get a noticeable whirlpool/dimple.

Its not going to make a difference I don't think. Its nice to have them in motion but that can be done with just a simple swirl from time to time. Totally up to you. One thing to think about though with them being motionless is you will be able to see any fermentation start.

Cheers
Jay

 

[Kickass]

80 F won’t kill your yeast. Most don’t brew at that temp because they don’t like the sensory byproducts, not because it’s hazardous to the yeast.

 

[Zwerg]

Thanks! I eventually cold crashed it and I have a nice layer of yeast sitting on the bottom now - just couldn't see it as it was happening. Good to know for the future.

 

[deuc224]

Ive made a 5ml small amount of yeast grow but it took days to wake up but it did grow. The yeast was about 2 years old on 7ml of wort.