Did I kill my yeast?

[okeemike]

Hi guys... second time brewer, first time poster.

I took my yeast out of the fridge for about 8 hours, and then put it BACK into the fridge when I realized I would not get to it. I took it out again the next afternoon, and let it warm for a few hours before pitching. Could the warming/cooling/warming have killed it?

Here's the full story:

I brewed an extract batch over the weekend. I wasn't able to get the batch to cool down enough to pitch (plus, the wife was complaining about the mess), so I moved it to the primary fermenter, and put it in my freezer (temperature controlled at about 58-ish degrees).

The next afternoon, I finally got around to pitching my yeast. Now, about 12 hours later, I don't see any activity.

Should I get another tube of yeast, and try another round?

NOTE: I'm using WLP810, San Francisco Lager (hence, the colder temp for fermentation)

 

[okeemike]

On a second look, it appear my temps were wrong. Just checked, and it looks like my batch is at 54 (measured the water in my blow off bucket), and the range for the yeast is 58-65. So, I cranked it up to 62, and will wait for things to warm up.

In the mean time, could having the yeast at that temp (54) have killed it?

 

[punkerdru]

Nah, it would just slow it down. Bring the temp up to 60 and wait a day or two, it'll be fine.

 

[GulfCoastGirl]

I seriously doubt bringing the yeast up to room temp and then re-refrigerating would kill yeast. I've done it a few times with no ill effects.

I notice your post doesn't mention making a starter. What size is your batch? Did you make a starter? Typically you would make a starter with the liquid yeast vials. Could it be you under-pitched????

 

[shawnbou]

54°F is not cold enough to kill yeast, so don't worry. I keep yeast in my fridge at around 37°F. It puts it to sleep, but when it gets back to proper temperatures it will work. Yeast are pretty hardy: they need to get a little colder or a lot hotter to be killed. Freezing is bad. Anything over 100°F is bad.

What you're experiencing is just lag time. It often takes more than 12 hours for fermentation to show any signs of activity. Wait another 24-36 hours, and if you still don't see any activity, take a gravity reading. That is the only way to know if fermentation is happening or not.

 

[sonex]

your lag time could be quit long since you will have to wait for the beer to warm up, then the yeast will need to wake up, plus you under pitched. Don't be surprised if it takes a couple days to see activity.

 

[Lyikos]

Yeast is pretty difficult to kill to the point of complete unviability, unless you froze it completely you don't need another vial for the fermentation to start, it will just take longer. Unless 3 days have passed with no signs of activity you're fine. How many gallons is the batch? Unless its 2 gallons or less usin only one vial without propagting it in a starter first wll result in a slow start anyway.

 

[MotorcycleMatt]

if you didnt make a good sized starter for a lager then you severely underpitched. It could take a while for it take off.

 

[TimpanogosSlim]

your lag time could be quit long since you will have to wait for the beer to warm up, then the yeast will need to wake up, plus you under pitched. Don't be surprised if it takes a couple days to see activity.

*shrug* I've fermented nottingham in the mid 50's, and that's an ale strain.

 

[okeemike]

I notice your post doesn't mention making a starter. What size is your batch? Did you make a starter? Typically you would make a starter with the liquid yeast vials. Could it be you under-pitched????

No, I didn't make a starter. In all the reading I've done, I didn't get the impression that it was really necessary...am I mistaken?

I brewed five gallons.

On a related note, is it possible to use too MUCH yeast?

 

[okeemike]

Thanks for the feedback, everyone! Sounds like I just need to be more patient, and wait for this stuff to take hold.

 

[okeemike]

Unless its 2 gallons or less usin only one vial without propagting it in a starter first wll result in a slow start anyway.

That's good advice, thanks. Lesson learned...make a starter every time.

 

[GulfCoastGirl]

On a related note, is it possible to use too MUCH yeast?

Yep, that would be called over-pitching.

This is from the White Labs website: http://www.wyeastlab.com/com-pitch-rates.cfm



Effect of Pitch Rate on Beer Flavor

Pitch rates, in addition to strain, temperature, and gravity, make a dramatic difference in the final flavor and aroma profile of any beer. The pitch rate will have a direct effect on the amount of cell growth during a fermentation. Cell growth decreases as pitch rates increase. Ester production is directly related to yeast growth as are most other flavor and aroma compounds.

A low pitch rate can lead to:

• Excess levels of diacetyl
• Increase in higher/fusel alcohol formation
• Increase in ester formation
• Increase in volatile sulfur compounds
• High terminal gravities
• Stuck fermentations
• Increased risk of infection

High pitch rates can lead to:

• Very low ester production
• Very fast fermentations
• Thin or lacking body/mouthfeel
• Autolysis (Yeasty flavors due to lysing of cells)

I'm a new brewer myself so I understand the frustration of just wanting to buy a kit, brew it up and have it come out perfect. Unfortunately there is much we need to learn to produce good beers so we just have to suck it up and do some reading.

I had zero understanding of yeast rates a few months ago. I still don't know much, but I've read a bunch and feel like I'm starting to "get it".

I like the software BeerSmith for figuring out pitch rates and what size starters to make. I also really like Mr. Malty's on-line pitch rate calculator http://www.mrmalty.com/calc/calc.html

Either of those should tell you how much yeast you should be pitching.

 

[okeemike]

Either of those should tell you how much yeast you should be pitching.

Holy cats. Based on the website, I should have pitched either three vials of yeast, or two vials, plus a liter of starter.

 

[GulfCoastGirl]

Holy cats. Based on the website, I should have pitched either three vials of yeast, or two vials, plus a liter of starter.

You could do it with one vial.... but you would have had to create the starter then "step it up". Yeast isn't cheap so it's a great idea to learn how to step up a starter (watch this video) http://billybrew.com/stepping-up-a-yeast-starter


I'd also recommend reading at least the first page of this thread: https://www.homebrewtalk.com/f163/yeast-washing-illustrated-41768/. Washing (or harvesting) your used yeast is SUPER easy and will really let you save a ton of money on yeast. That thread demonstrates the process really well. I read the first few pages and was able to do this myself with no problem. My only problem now is the growing number of pint jars filled with yeast I have in my fridge. Not a bad problem to have